JP2014093601A - Radio communication system - Google Patents

Abstract

Generation of overreach between different wireless communication systems is suppressed.
A first terminal station, a second terminal station, a base station that is wirelessly connected to the first and second terminal stations, and between the first and second terminal stations and the base station. In a wireless communication system including a relay station that relays wirelessly, information communicated between the first and second terminal stations and the base station includes a system code for identifying the wireless communication system. The first terminal station can communicate with the second terminal station via the base station using a base station wave, and can communicate with the second terminal station without going through the base station. When the base station wave is received, the relay station converts it into a direct wave and outputs it wirelessly.When the direct wave is received, the relay station converts it into a base station wave and outputs it wirelessly. If the direct wave does not contain the system code of the wireless communication system, transmission of the relay station Force to lower the reception level.
[Selection] Figure 6

Description

  The present invention relates to a wireless communication system including a base station, a plurality of terminal stations wirelessly connected to the base station, and a relay station that wirelessly relays between the base station and the terminal station.

  In a conventional wireless communication system, such as a disaster prevention wireless system, a control station and a base station are connected by, for example, a microwave line, and a relay station and a plurality of terminal stations are wirelessly connected to the base station. In this wireless communication system, base station communication via a base station is performed between a control station and a terminal station, between a terminal station and a terminal station, or direct communication is performed between a terminal station and a terminal station without passing through a base station. Direct communication between terminal stations is possible. In addition, a direct communication relay station that relays the base station communication wave (base station wave) and the direct communication wave between the terminal stations (direct wave) is installed, and wireless communication is performed between the base station and the terminal station by the direct communication relay station. Relaying is done.

  The direct communication relay station is installed, for example, in a dead zone in the base station area, and automatically relays base station waves and direct waves. As a result, wireless communication can be performed between a terminal station in an area that is in a dead zone and capable of direct communication with a direct communication relay station, and another terminal station in the control station or the base station area. Make it possible.

  By the way, when two different radio communication systems are adjacent to each other, for example, when disaster prevention radio systems of A city and B city are adjacent, direct communication relay stations installed in the respective systems interfere with each other. Overreach may occur. For example, when the coverage area of the direct wave output from the direct communication relay station of City A overlaps the coverage area of the direct wave output from the direct communication relay station of City B, the direct communication relay station of City A The direct wave output from the direct communication relay station or the direct wave output from the terminal station communicating with the direct communication relay station in city B is received. Thus, when overreach occurs, radio waves that should not be received are received.

  Patent Document 1 below discloses wireless communication including a control station, a base station connected to the control station, a wireless terminal connected to the base station, and a direct communication relay station that relays between the base station and the wireless terminal. A system is disclosed. However, the system of Patent Document 1 does not mention the correspondence to overreach.

JP 2012-85143 A

  An object of the present invention is to provide a wireless communication system capable of solving the above-described problems of the prior art and suppressing the occurrence of overreach between different wireless communication systems.

A typical configuration of the present invention for solving the above problems is as follows. That is,
Wireless communication between the first terminal station, the second terminal station, the base station wirelessly connected to the first and second terminal stations, and between the first and second terminal stations and the base station A wireless communication system comprising a relay station relaying at
The information communicated between the first and second terminal stations and the base station includes a system code for identifying the wireless communication system,
The first terminal station can perform base station communication that communicates with the second terminal station via the base station using a base station wave, and the second terminal station does not pass through the base station. Direct communication between terminal stations that communicate with other terminal stations using direct waves,
When the relay station receives the base station wave, the relay station converts the direct wave to the radio wave and outputs the radio wave, and when receiving the direct wave, the relay station converts the radio wave to the base station wave and outputs the radio wave. When the system code of the said radio | wireless communications system is not included, the radio communication system characterized by reducing the transmission output and the reception level of the said relay station.

  According to the present invention, occurrence of overreach between different wireless communication systems can be suppressed.

It is a block diagram of the radio | wireless communications system in embodiment of this invention. It is a block diagram of the control station in embodiment of this invention. It is a block diagram of the base station in embodiment of this invention. It is a block diagram of a relay station in an embodiment of the present invention. It is a block diagram of the terminal station in embodiment of this invention. It is a figure which shows operation | movement of the relay station in embodiment of this invention. It is a figure which shows the radio | wireless carrier frequency allocation used with the radio | wireless communications system in embodiment of this invention. It is a figure which shows the flame | frame structure used with the radio | wireless communications system in embodiment of this invention.

(Configuration of wireless communication system)
The configuration of the wireless communication system of this embodiment will be described with reference to FIG. FIG. 1 is a diagram illustrating a configuration of a wireless communication system according to an embodiment of the present invention. In the example of FIG. 1, the disaster prevention radio system of City A and the disaster prevention radio system of City B are installed adjacent to each other, the direct communication relay station (hereinafter referred to as relay station) 40A of the disaster prevention radio system of City A, and the disaster prevention system of City B A case where the relay station 40B of the wireless system is installed at a position where overreach occurs is shown.

  The radio communication system of FIG. 1 is defined by, for example, “Prefectural / Municipal Digital Mobile Communication System” or “Municipal Digital Mobile Communication System” of the standard ARIB STD-T79 (Association of Radio Industries and Businesses-T79). Is a digital wireless system. This digital radio system is configured to perform a communication connection service for direct communication between terminal stations via base stations or between terminal stations not via base stations.

As shown in FIG. 1, the radio communication system A of the present embodiment is mainly movable with a control station 10A, a base station 30A connected to the control station 10A via a wired or microwave line, and a relay station 40A. Terminal station 50A. The radio communication system B mainly includes a control station 10B, a base station 30B connected to the control station 10B by a wired or microwave line, a relay station 40B, and a movable terminal station 50B (not shown). Prepare. The relay station 40A and the relay station 40B are installed adjacent to each other.
The communication area 401 of the relay station 40A and the communication area 402 of the relay station 40B overlap each other, and the relay station 40A and the relay station 40B are installed at positions where overreach occurs.

  In the example of FIG. 1, one base station 30 of each of the radio communication system A and the radio communication system B is shown, but two or more base stations 30 may be provided. Further, although one relay station 40 is shown for each of the wireless communication system A and the wireless communication system B, two or more relay stations 40 may be provided, and a plurality of relay stations 40 may be installed for one base station 30. . Further, as for the terminal stations 50 of the wireless communication system A and the wireless communication system B, one terminal station 50A of the wireless communication system A is shown in FIG. 1, but there may also be a terminal station 50B of the wireless communication system B. . There may be two or more terminal stations 50A and 50B, respectively. In addition, when representing the control station, it is referred to as the control station 10. When representing a base station, it is referred to as a base station 30. When a relay station is represented, it is called a relay station 40. When representing the terminal station 50, the terminal station 50 is referred to as a terminal station 50.

  In the example of FIG. 1, between the base station 40 and the terminal station 50 (frequency f1, F1), between the base station 40 and the relay station 40 (frequency f1, F1), the relay station 40 and the terminal station 50, (Frequency W) is connected so that wireless communication is possible, for example, by digital radio of 260 MHz band.

  FIG. 7 shows an example of radio carrier frequency allocation permitted to be used in a digital radio system using the digital radio technology defined in the standard ARIB STD-T79. In FIG. 7, for example, in the uplink direction, that is, in the direction from the terminal station to the base station, a plurality of waves (f1, f2,...) Are recognized with a radio carrier f of about 260 MHz to 266 MHz and a width of 25 kHz. . In the downstream direction, that is, in the direction from the base station to the terminal station, a radio carrier F having a frequency of about 269 MHz to 275 MHz, 9 MHz away from 260 MHz in the upstream direction, and a plurality of waves (F1, F2,...) With a width of 25 kHz. It recognized. Therefore, in the communication of the digital wireless system, the frequencies in the upstream direction f1, f2,..., The downstream directions F1, F2,. Each system can use one or a plurality of radio carriers according to the scale. In the example of FIG. 1, the base station 30A uses f1 and F1, and the base station 30B uses f2 and F2.

  Further, according to the standard ARIB STD-T79, the base station 30 is connected between the terminal stations, for example, the terminal station 50 located within the communication area 301 of the base station 30A and the terminal station 50 located outside the communication area 301, for example. The radio carrier W is recognized as a direct wave so that direct communication between terminal stations can be performed without going through. This wireless carrier W also has a bandwidth of 25 kHz, and a dozen waves (W1, W2,...) Are recognized. In the example of FIG. 1, W1 is used as a direct wave.

  Further, each wireless carrier, for example, F1 and f1, is divided into frames as shown in FIG. 8, and after the frame is further divided into four slots, the control channel C and communication channels S1, S2, S3 are placed in the slots. Is assigned. Note that the communication channels S1, S2, and S3 are referred to as communication channels (or communication channels) S. Here, for example, one frame is 40 ms, and one slot is 10 ms. The control channel C is a channel for performing connection control of a wireless line, and the communication channel S is a channel for performing a telephone call and data communication. FIG. 8 shows an example, and the number of uplink and downlink pair waves, the number of control channels, the number of communication channels, and the like can be appropriately changed according to the scale of the system and the purpose of use.

The control station will be described with reference to FIG.
FIG. 2 shows the configuration of the control station in this embodiment. The control station 10 is an interface (IF) that is a connection unit for connecting the control station control device 11, the storage unit 12, the control table 13, the operation management device 14, the control station control device 11 and the base station 30. ) IF15. The control station control device 11 includes a line control device 11a and a control station control unit 11b.

  The line control device 11a maintains and manages the communication connection and the service area between the base station 30 and the plurality of terminal stations 50 in the digital wireless system (wireless communication system A or B). The call control or the control for setting the communication route is performed.

The control station control unit 11b controls each component constituting the control station 10 and the entire control station 10.
Note that the control station control device 11 may be configured integrally with one of the base stations 30 or may be installed in a place distant from each other as shown in FIG.

  The storage unit 12 stores a system code as an identifier for identifying the digital wireless system to which the control station 10 belongs. For example, the system code of the digital radio system A is stored. These are input by an operator via an operation display unit (not shown) of the control station 10, for example.

The control table 13 includes an operation display unit (not shown), a microphone, a speaker (not shown), etc., and has a control function capable of monitoring, interrupting, and forcibly disconnecting other calls. The operator operates the control table 13. Then, operations such as communicating with each terminal station 50 in the wireless communication system and issuing an urgent instruction to each terminal station 50 are performed.
In addition, the control table 13 determines whether the system code included in the received information is appropriate, for example, whether it matches the system code of its own system, so as not to receive information transmitted from different wireless communication systems. Is checked with reference to the system code of the own system stored in the storage unit 12. Received information other than addressed to its own system is treated as invalid information.

  The operation management device 14 includes an operation display unit (not shown), has a function of setting and maintaining basic management information of the digital wireless system such as system status confirmation, and is mainly an administrator of the digital wireless system. However, it is comprised so that it may operate using the said operation display part.

The base station will be described with reference to FIG.
FIG. 3 shows the configuration of the base station in this embodiment. The base station 30 includes an IF 35 that is an interface (IF) that is a connection unit for connecting the control unit 31, the storage unit 32, the transmission unit 33, the reception unit 34, and the base station 30 and the control station 10. Prepare.

  The transmission unit 33 includes an antenna 33a, converts the baseband signal output from the control unit 31 into a radio frequency signal, and transmits the radio frequency signal to the terminal station 50 and the relay station 40 being served by the base station via the antenna 33a. Wireless transmission is performed using the wireless carrier F. The receiving unit 34 includes an antenna 34a, receives a radio frequency signal using the radio carrier f from the terminal station 50 and the relay station 40 being served by the base station via the antenna 34a, converts the radio frequency signal into a baseband signal, and controls the baseband signal. To the unit 31.

The storage unit 32 stores the system code of the digital wireless system to which the base station 30 belongs. These are input by an operator via an operation display unit (not shown) of the base station 30, for example.
The control unit 31 controls each constituent unit constituting the base station 30 and the entire base station 30.

The relay station will be described with reference to FIG.
FIG. 4 shows the configuration of the relay station in this embodiment. The relay station 40 includes a control unit 41, a storage unit 42, a base station wave radio unit 43, and a direct wave radio unit 44.
The base station wave radio unit 43 is connected to an antenna 43a, converts a signal of the frequency W output from the direct wave radio unit 44 through the control unit 41 into a frequency f, and wirelessly transmits the signal through the antenna 43a. I do. The base station wave radio unit 43 receives a radio signal of frequency F via the antenna 43 a and outputs the radio signal to the direct wave radio unit 44 via the control unit 41.

The direct wave radio unit 44 is connected to the antenna 44a, converts the signal of the frequency F output from the base station wave radio unit 43 via the control unit 41 into the frequency W, and performs radio transmission via the antenna 44a. Do. The direct wave radio unit 44 receives a radio signal having a frequency W via the antenna 44 a and outputs the radio signal to the base station wave radio unit 43 via the control unit 41.
Note that the operation for converting the above-mentioned frequency W signal to the frequency f and the operation for converting the frequency F signal to the frequency W are performed by only one of the base station wave radio unit 43 and the direct wave radio unit 44. It is also possible to have a configuration that is performed, or a configuration that is performed by the control unit 41 is possible.

Also, one end of a variable attenuator 44b is connected to the antenna 44a, a terminal B of a switch 44c is connected to the other end of the variable attenuator 44b, and a terminal A of the switch 44c is connected to the direct wave radio unit 44. The terminal C of the switch 44c is connected to one end of the termination resistor 44d, and the other end of the termination resistor 44d is grounded.
The switch 44c connects the direct wave radio unit 44 and the other end of the variable attenuator 44b according to a control signal (not shown) from the control unit 41, or connects the direct wave radio unit 44 and one end of the terminating resistor 44d. Switch the connection. The variable attenuator 44b changes the amount of attenuation according to a control signal (not shown) from the control unit 41.

  The storage unit 42 stores the system code of the digital wireless system to which the relay station 40 belongs. The storage unit 42 stores a threshold value for determining whether or not the received direct wave is equal to or higher than a predetermined level. These are input by an operator via an operation display unit (not shown) of the relay station 40, for example.

The control unit 41 controls each constituent unit constituting the relay station 40 and the entire relay station 40.
Further, the control unit 41 determines whether or not the system code included in the direct wave information (frequency W) received from the other relay station 40 is an appropriate code, for example, whether or not it matches the system code of its own system. Is checked with reference to the system code of the own system stored in the storage unit 42. Preferably, the control unit 41 checks whether the reception level of the direct wave received from the other relay station 40 is equal to or higher than a predetermined threshold value.
When it is different from the system code of its own system, that is, when it is a system code of a wireless communication system that should not be received originally, and the reception level of the direct wave received from another relay station 40 is greater than or equal to a predetermined threshold The control unit 41 changes the set value of the variable attenuator 44b of the relay station 40 to increase the attenuation. When the configuration is such that a plurality of set values of the variable attenuator 44b can be set, the set value is changed step by step, and the attenuation amount is increased step by step. When the reception level of the direct wave information received from another relay station 40 is not equal to or higher than a predetermined threshold, the set value of the variable attenuator 44b of the relay station 40 is not changed.

Further, when the set value of the variable attenuator 44b is changed, the attenuation amount of the variable attenuator 44b is changed so that the transmission output from the relay station 40 is within the allowable range at the time of applying for the radio wave license. For example, the attenuation amount of the variable attenuator 44b is changed so as to be equal to or greater than the minimum value of the transmission output at the time of applying for the radio wave license (for example, 50% of the predetermined transmission output).
If the transmission output deviates from the allowable range at the time of radio wave application, the direct wave radio unit 44 of the relay station 40 and the terminating resistor 44d are connected to stop transmission from the relay station 40, An alarm indicating that the transmission output deviates from the allowable range is displayed on the operation display unit of the relay station 40. Thereby, the operator of the said relay station 40 can reapply so that the transmission output of the said relay station 40 may be in an appropriate range.

Thus, by increasing the attenuation amount of the variable attenuator 44b, the reception level of the direct wave received from the other relay station 40 is lowered, and the transmission output of the direct wave transmitted from the relay station 40 is lowered. Therefore, an overreach state with another relay station 40 can be suppressed. In addition, when the configuration is such that a plurality of setting values of the variable attenuator 44b can be set, the setting value is changed step by step, so that the variable attenuator 44b can be easily set to an appropriate value.
When the system code included in the received information is not an appropriate code, the received information is ignored as invalid information.

  Further, the control unit 41 changes the set value of the variable attenuator 44b as described above, and the reception level of the direct wave received from the other relay station 40 is equal to or greater than a predetermined threshold even when the attenuation amount is maximized. Connects the direct wave radio unit 44 of the relay station 40 and the terminating resistor 44d, stops transmission from the relay station 40 and reception from other relay stations 40, and displays the operation display of the relay station 40 An alarm indicating that the reception level of the received direct wave deviates from the allowable range is displayed on the section.

  In addition, when the system code included in the received direct wave information is not an appropriate code and the reception level of the received direct wave is equal to or greater than a predetermined threshold, the control unit 41 determines that the relay station 40 is in the overreach state. Information indicating that it is present or information indicating that the transmission output of the direct wave transmitted by the transmission source relay station 40 is excessive is displayed as an alarm. At this time, information (for example, a system name and a system code) for identifying a wireless communication system having a system code included in the received direct wave information is displayed on the operation display unit of the relay station 40. Thereby, the operator of the relay station 40 can know which radio communication system the relay station 40 is interfering with.

In addition, the control unit 41 determines that the system code (system code B in this example) included in the direct wave information received from the other relay station 40 is not an appropriate code, and the received level of the received direct wave is equal to or higher than a predetermined threshold value. In this case, notification information indicating that “overreach to another system (for example, system A)” or transmission output of a direct wave transmitted from the transmission source relay station 40 is sent to the transmission source relay station 40. Information that is excessive is transmitted by direct wave. The notification information includes, for example, a transmission source address that is the address of the relay station 40A and a destination address that is the address of the destination relay station 40B.
Thereby, the relay station 40B of the transmission source system B increases the attenuation amount of the variable attenuator 44b of the relay station 40B or stops transmission from the relay station 40B, and displays the operation display of the relay station 40B. An alarm indicating that the state is an overreach state is displayed on the operation display unit of the control unit 10B.

Further, the control unit 41 may be configured to enter a test mode in which a direct wave is transmitted periodically or at a predetermined timing in order to search for another relay station 40 that is overreached. In the case of this configuration, direct wave relay is normally performed as the relay station 40, and when the test mode timing comes, a direct wave for testing is transmitted when direct wave relay is not performed. The test direct wave includes an address of the relay station 40 that is a transmission source, a system code, and information indicating that the test mode is set.
When the direct wave relay is performed when the timing of the test mode arrives, the test mode is entered after the direct wave relay is completed, and the test direct wave is transmitted.

For example, the timing of the test mode is preferably stored as time information in the storage unit 42 of each relay station 40 so that each relay station 40 enters the test mode at substantially the same timing. In this way, the operation of searching for the relay station 40 that is overreach can be performed efficiently.
As described above, when the relay station 40 is configured to have the test mode function, the transmission output of the relay station 40 can be appropriately set even when the relay station 40 is unmanned, and overreach can be suppressed. .

The terminal station will be described with reference to FIG.
FIG. 5 shows the configuration of the terminal station in this embodiment. The terminal station 50 includes a control unit 51, a storage unit 52, a transmission unit 53, a reception unit 54, a changeover switch 55 for switching between transmission and reception, an antenna 55a, an operation display unit 57, a microphone 58, and a speaker 59. Prepare.
Based on the operator's instruction received by the operation display unit 57, the terminal station 50 performs a base station communication mode in which communication is performed using the wireless carriers f and F via the base station 30 and a wireless carrier without using the base station 30. Any of the direct communication modes between terminals that perform direct communication between terminals using W can be selected.

  The storage unit 52 stores the above-described system code. This is input by the operator via the operation display unit 57, for example. Further, the storage unit 52 stores whether the communication mode at that time is the base station communication mode or the inter-terminal direct communication mode.

The control unit 51 controls the above-described components configuring the terminal station 50 and the terminal station 50 as a whole. For example, the control unit 51 converts the audio signal output from the microphone 58 into a baseband signal and outputs the baseband signal to the transmission unit 53. Then, the baseband signal output from the receiving unit 54 is converted into an audio signal and output to the speaker 59.
In addition, the control unit 51 determines whether or not the system code included in the received information is appropriate so as not to receive information transmitted from different wireless communication systems, for example, whether or not it matches the system code of its own system. Is checked with reference to the system code of the own system stored in the storage unit 52. Received information other than addressed to its own system is treated as invalid information.

The transmission unit 53 converts the baseband signal output from the control unit 51 into a radio frequency signal, and performs wireless transmission via the antenna 55a. The receiving unit 54 receives a radio frequency signal via the antenna 55a, converts it to a baseband signal, and outputs the baseband signal to the control unit 51. The changeover switch 55 connects the transmission unit 53 or the reception unit 54 and the antenna 55a based on an instruction from the control unit 51.
When the above-described base station communication mode is selected, the transmission unit 53 wirelessly transmits a radio frequency signal using the radio carrier f to the base station 30, and the reception unit 54 receives the base station via the antenna 55a. A radio frequency signal using a radio carrier F is received from 30. When the inter-terminal direct communication mode is selected, the transmission unit 53 wirelessly transmits a radio frequency signal using the radio carrier W, and the reception unit 54 uses the radio carrier W via the antenna 55a. Receive.

The control station control device 11, the base station control unit 31, the relay station control unit 41, and the terminal station control unit 51 each have a hardware configuration such as a CPU (Central Processing Unit) and an operation program for the control device and the control unit. The CPU operates according to this operation program.
Further, the control station storage unit 12, the base station storage unit 32, the relay station storage unit 42, and the terminal station control unit 52 can be configured by a semiconductor memory, a hard disk device, or the like.

The operation in the case where overreach occurs between the relay station 40A and the relay station 40B will be described with reference to FIGS. FIG. 6 is a diagram illustrating the operation of the relay station in the present embodiment.
In FIG. 1, the relay station 40A is in a state where its direct wave radio unit 44 can transmit or receive a direct wave of frequency W. The direct wave transmitted from the relay station 40A includes the source system code A. Further, the relay station 40B is in a state where the direct wave radio unit 44 can transmit or receive a direct wave of the frequency W. The direct wave transmitted from the relay station 40B includes the source system code B.

  First, when the relay station 40A receives the direct wave information of the frequency W (step S1 in FIG. 6), the relay station 40A checks the system code included in the direct wave information (step S2). If the checked system code is the system code A of the wireless communication system A to which the relay station 40A belongs (A in step S2), the received information is converted into a base station wave of the frequency f1 and transmitted. This is a normal relay operation as the relay station 40.

Further, when the system code included in the received direct wave information is not system code A (in this example, it is system code B) (B in step S2), relay station 40A determines that the reception level of the received direct wave is It is checked whether or not it is equal to or greater than a predetermined threshold (step S3).
If the reception level of the received direct wave is equal to or higher than a predetermined threshold (Yes in step S3), information (for example, system name B) for identifying the wireless communication system having the system code B included in the received direct wave information is stored. The alarm display indicating the overreach state is displayed on the operation display unit of the relay station 40A (step S4). If the received level of the received direct wave information is not equal to or higher than the predetermined threshold (No in step S3), the process is terminated.

Further, the relay station 40A transmits, to the transmission source relay station 40B, direct notification information indicating that “overreach to another system (system A in this example)” (step S5). The notification information includes, for example, a system code A that is the transmission source of the notification information and a system code B that is received from another relay station 40.
Thereby, the relay station 40B increases the attenuation amount of the variable attenuator 44b of the relay station 40B or stops transmission from the relay station 40B, and the operation display unit of the relay station 40B or the operation display unit of the control board 10B. In addition, an alarm display indicating an overreach state is performed.

Further, the relay station 40A increases the attenuation amount of the variable attenuator 44b of the relay station 40A (step S6).
At this time, the relay station 40A changes the attenuation amount of the variable attenuator 44b so that the transmission output from the relay station 40A is within the allowable range at the time of applying for the radio wave license. If the transmission output deviates from the allowable range at the time of the radio wave application (Yes in step S7), the transmission from the relay station 40A is stopped and the transmission output is within the allowable range on the operation display unit of the relay station 40A. An alarm indicating that the state deviates from the above is displayed (step S8). If the transmission output does not deviate from the permissible range at the time of radio wave application (No in step S7), the process is terminated.

According to this embodiment, at least the following effects can be obtained.
(1) Since the relay station reduces the transmission output and the reception level when the system code included in the received direct wave information is not an appropriate code, it is possible to suppress the occurrence of overreach.
(2) Since the relay station displays the overreach state when the system code included in the received direct wave information is not an appropriate code, the operator can easily know that it is in the overreach state. Can do.
(3) When the system code included in the received direct wave information is not an appropriate code, the relay station transmits an overreach state to the transmission source relay station, further suppressing the occurrence of overreach. can do.
(4) If the relay station is configured to enter a test mode in which a direct wave is transmitted periodically or at a predetermined timing in order to search for another relay station that is overreached, further overreach Occurrence can be suppressed.

In addition, this invention is not limited to embodiment mentioned above, It can implement in various deformation | transformation and a combination. For example, in the process of FIG. 6 described above, the process of step S3 may be always performed when the direct wave of the other system code B is received without performing the process of step S3.
In addition, the present invention is understood not only as a system for executing processing according to the present invention, but also as an apparatus and method, a program for realizing such a method and system, and a recording medium for recording the program. can do.
In addition, the present invention may be configured such that the CPU performs control by executing a control program stored in the memory, or may be configured as a hardware circuit that does not use the CPU.

The present specification includes at least the following configurations. That is,
The first configuration is
Wireless communication between the first terminal station, the second terminal station, the base station wirelessly connected to the first and second terminal stations, and between the first and second terminal stations and the base station A wireless communication system comprising a relay station relaying at
The information communicated between the first and second terminal stations and the base station includes a system code for identifying the wireless communication system,
The first terminal station can perform base station communication that communicates with the second terminal station via the base station using a base station wave, and the second terminal station does not pass through the base station. Direct communication between terminal stations that communicate with other terminal stations using direct waves,
When the relay station receives the base station wave, the relay station converts the direct wave to the radio wave and outputs the radio wave, and when receiving the direct wave, the relay station converts the radio wave to the base station wave and outputs the radio wave. When the system code of the said radio | wireless communications system is not included, the radio communication system characterized by reducing the transmission output and the reception level of the said relay station.

The second configuration is the wireless communication system of the first configuration,
When the received direct wave does not include the system code of the wireless communication system, the relay station has an excessive transmission output of the received direct wave with respect to the source of the received direct wave A wireless communication system, wherein information to the effect is wirelessly transmitted by the direct wave.

A third configuration is the wireless communication system of the first configuration or the second configuration,
When the received direct wave does not include a system code of the wireless communication system, the relay station displays information indicating that the received direct wave transmission output is excessive on the relay station. A wireless communication system.

A fourth configuration is the wireless communication system of the first configuration to the third configuration,
The wireless communication system, wherein the relay station enters a test mode in which a direct wave is transmitted at a predetermined timing in order to search for another relay station that is overreached.

  DESCRIPTION OF SYMBOLS 10 ... Control station, 11 ... Control station control apparatus, 11a ... Line control apparatus, 11b ... Control station control part, 12 ... Control station memory | storage part, 13 ... Control stand, 14 ... Operation management apparatus, 15 ... IF, 30 ... Base , 31 ... base station control unit, 32 ... base station storage unit, 33 ... base station transmission unit, 33a ... antenna, 34 ... base station reception unit, 34a ... antenna, 35 ... IF, 40 ... relay station, 41 ... relay Station control unit 42 ... Relay station storage unit 43 ... Base station radio unit 43a ... Antenna 44 ... Direct wave radio unit 44a ... Antenna 44b ... Variable attenuator 44c ... Switch 44d ... Termination resistance , 50 ... terminal station, 51 ... terminal station control unit, 52 ... terminal station storage unit, 53 ... terminal station transmission unit, 54 ... terminal station reception unit, 55 ... changeover switch, 55a ... antenna, 57 ... operation display unit, 58 ... microphone, 59 ... speaker.

Claims (1)

Wireless communication between the first terminal station, the second terminal station, the base station wirelessly connected to the first and second terminal stations, and between the first and second terminal stations and the base station A wireless communication system comprising a relay station relaying at
The information communicated between the first and second terminal stations and the base station includes a system code for identifying the wireless communication system,
The first terminal station can perform base station communication that communicates with the second terminal station via the base station using a base station wave, and the second terminal station does not pass through the base station. Direct communication between terminal stations that communicate with other terminal stations using direct waves,
When the relay station receives the base station wave, the relay station converts the direct wave to the radio wave and outputs the radio wave, and when receiving the direct wave, the relay station converts the radio wave to the base station wave and outputs the radio wave. When the system code of the said radio | wireless communications system is not included, the radio communication system characterized by reducing the transmission output and the reception level of the said relay station.

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