Radio station and communication method

Abstract

To provide a radio station and a communication method that are simple in configuration and capable of communicating in a plurality of communication modes in which at least one of frequency bands used and communication standards differ from each other.SOLUTION: A radio station 1 includes a switching instruction reception unit 11, a position determining unit 12, a mode selecting unit 13, a signal processing circuit 14, and a communication unit 15. The position determining unit 12 determines whether the radio station 1 is located within any of one or more regions indicating a geographical range associated with one of communication modes of the radio station 1. When the switching instruction reception unit 11 receives an instruction to switch to a transmission mode, the mode selecting unit 13 selects a first communication mode for the region in which the radio station 1 is determined to be located, or a second communication mode for when the radio station 1 is not located within any of the regions. The signal processing circuit 14 generates transmission data from an input signal according to the communication mode selected by the mode selecting unit 13.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a wireless station and a communication method.

Background Art

[0002] A wireless station mounted on a ship performs maritime wireless communication, specifically analog wireless communication in the international VHF (Very High Frequency) band during navigation. When the ship is docked at a port, the wireless station mounted on the ship performs wireless communication with a wireless station used on land using a land operation wireless frequency band close to the international VHF band. An example of a wireless station that performs wireless communication in a plurality of frequency bands is disclosed in Patent Document 1.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When the first PTT (Push To Talk) switch is pressed, the wireless communication device disclosed in Patent Document 1 performs transmission processing at the first frequency, and when the second PTT switch is pressed, it performs transmission processing at the second frequency. In the wireless communication device disclosed in Patent Document 1, since a PTT switch is provided for each frequency, the structure of the wireless station is complicated.

[0005] The present invention has been made in view of the above circumstances, and an object thereof is to provide a wireless station and a communication method that can communicate in a plurality of communication modes with at least one of the used frequency bands and communication standards being different from each other with a simple configuration.

Means for Solving the Problems

[0006] To achieve the above object, a wireless station according to a first aspect of the present invention is a wireless station that communicates in a plurality of communication modes in which at least one of the operating frequency bands and communication standards is different from each other, a position determination unit that determines whether or not the wireless station is located inside any one of at least one predetermined area indicating a geographical range associated with any one of the communication modes; a switching instruction reception unit that receives an instruction to switch between a transmission mode and a reception mode of the wireless station; when the switching instruction reception unit receives an instruction to switch to the transmission mode, if the position determination unit determines that the wireless station is located inside the area, a first communication mode corresponding to the area where the wireless station is located is selected from the plurality of communication modes, and if the position determination unit determines that the wireless station is not located inside any of the areas, a second communication mode, which is a communication mode different from the first communication mode, is selected; a mode selection unit; a signal processing circuit that generates transmission data corresponding to the first communication mode or the second communication mode selected by the mode selection unit from an input signal; a communication unit that generates a transmission signal from the transmission data generated by the signal processing circuit and transmits the transmission signal; and includes.

[0007] Preferably, the communication unit receives signals in the respective operating frequency bands of the communication modes, when the switching instruction reception unit receives an instruction to switch to the transmission mode and the position determination unit determines that the wireless station is located inside the area, if the communication unit has received a signal in the operating frequency band of the second communication mode during a target period, which is a recently defined period, the second communication mode is selected, and if the communication unit has not received a signal in the operating frequency band of the second communication mode during the target period, the first communication mode is selected.

[0008] Preferably, when the mode selection unit receives an instruction to switch to the transmission mode from the switching instruction reception unit and the position determination unit determines that the radio station is not located inside any of the regions, if the communication unit has received a signal in the use frequency band of the first communication mode during the target period, the first communication mode is selected; if the communication unit has not received a signal in the use frequency band of the first communication mode during the target period, the second communication mode is selected.

[0009] Preferably, when the mode selection unit receives an instruction to switch to the transmission mode from the switching instruction reception unit and the position determination unit determines that the radio station is located inside the region, the first communication mode compliant with the communication standard of the public line is selected.

[0010] Preferably, the position determination unit determines whether the radio station is located inside the region included in the area where the public line can be connected.

[0011] Preferably, when the mode selection unit receives an instruction to switch to the transmission mode from the switching instruction reception unit and the position determination unit determines that the radio station is not located inside any of the regions, the second communication mode for performing analog radio communication using the international VHF (Very High Frequency) band as the use frequency band is selected.

[0012] Preferably, when the mode selection unit receives an instruction to switch to the transmission mode from the switching instruction reception unit and the position determination unit determines that the radio station is not located inside any of the regions, the second communication mode for performing digital radio communication using the frequency band assigned to business radio communication as the use frequency band is selected.

[0013] Preferably, when the mode selection unit receives an instruction to switch to the transmission mode from the switching instruction reception unit and the position determination unit determines that the radio station is located inside the area, the mode selection unit selects the first communication mode that performs analog radio communication using the international VHF band as the used frequency band.

[0014] Preferably, the position determination unit determines whether the radio station is located inside the area included in an area where analog radio communication using the international VHF band is possible.

[0015] Preferably, when the mode selection unit receives an instruction to switch to the transmission mode from the switching instruction reception unit and the position determination unit determines that the radio station is not located inside any of the areas, the mode selection unit selects the second communication mode compliant with the communication standard of the public switched telephone network.

[0016] Preferably, the switching instruction reception unit receives an instruction to switch between the transmission mode and the reception mode from a single operation switch that switches between the transmission mode and the reception mode by a mechanical operation.

[0017] Preferably, the position determination unit determines whether the radio station is located inside any of a plurality of the areas.

[0018] Preferably, the used frequency band and the communication standard of the first communication mode corresponding to each of the areas are the same as each other.

[0019] Preferably, at least one of the used frequency band and the communication standard of the first communication mode corresponding to at least one of the areas is different from the used frequency band and the communication standard of the first communication mode corresponding to the other areas.

[0020] A communication method according to a second aspect of the present invention is a communication method performed by a radio station that performs communication in a plurality of communication modes in which at least one of a used frequency band and a communication standard is different from each other, For at least one predetermined area indicating a geographical range associated with any of the communication modes, determine whether the wireless station is located inside any of the areas, Receive an instruction to switch between the transmission mode and the reception mode of the wireless station, When receiving an instruction to switch to the transmission mode, if it is determined that the wireless station is located inside the area, select a first communication mode corresponding to the area where the wireless station is located from among the plurality of communication modes; if it is determined that the wireless station is not located inside any of the areas, select a second communication mode, which is a communication mode different from the first communication mode, Generate transmission data corresponding to the selected first communication mode or second communication mode from the input signal, Generate a transmission signal from the transmission data and transmit the transmission signal.

Advantages of the Invention

[0021] According to the present invention, the wireless station selects the first communication mode when the wireless station is located inside the area, and selects the second communication mode when the wireless station is not located inside the area. The wireless station generates transmission data corresponding to the selected first communication mode or second communication mode from the input signal, and transmits a transmission signal generated from the transmission data. Thereby, it is possible to provide a wireless station and a communication method capable of communicating in a plurality of communication modes with a simple configuration.

Brief Description of the Drawings

[0022]

Figure 1

Figure 2

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Figure 17

Figure 18

Embodiments for Carrying Out the Invention

[0023] Hereinafter, the wireless station and the communication method according to the embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or equivalent parts are denoted by the same reference numerals.

[0024] (Embodiment 1) The wireless station 1 shown in FIG. 1 is a wireless communication device capable of communicating in a plurality of communication modes in which at least one of the operating frequency band and the communication standard is different from each other. As an example, the wireless station 1 communicates in either a communication mode of performing analog wireless communication in the 150 MHz band which is an international VHF (Very High Frequency) band or a communication mode of performing wireless communication conforming to the standard of a public network, for example, LTE (Long Term Evolution) communication. The wireless station 1 selects one of the communication modes according to whether it is located inside at least one predetermined area indicating a geographical range associated with one of the communication modes, and performs communication in the selected communication mode. The association between the communication mode used in the wireless station 1 and the area and the communication mode is arbitrarily set.

[0025] In the example of FIG. 1, one area 101 associated with the communication mode of performing LTE communication is defined. When the wireless station 1 is located inside the area 101, it communicates with the LTE communication device 201 by LTE communication. The LTE communication device 201 is any communication device capable of connecting to an LTE public network, such as, for example, an IP (Internet Protocol) transceiver, a smartphone, or the like. When the wireless station 1 is not located inside the area 101, that is, when it is located outside the area 101, it communicates with the VHF communication device 202 by international VHF communication. The VHF communication device 202 is, for example, a marine wireless communication device mounted on a ship. Since the wireless station 1 automatically switches the communication mode according to whether its own device is located inside the area 101, it does not require a PTT (Push To Talk) switch for each frequency, and the configuration is simple.

[0026] The area 101 indicates a geographical range arbitrarily defined based on the center position and the radius. The inside of the area 101 indicates the boundary of the area 101 and the area inside the boundary of the area 101. The center position of the area 101 is uniquely specified by, for example, latitude and longitude. The area 101 preferably includes an area where communication in the communication mode associated with the inside of the area 101 is possible, for example, an area where connection to an LTE public network is possible.

[0027] As shown in FIG. 2, the radio station 1 includes a switching instruction reception unit 11, a position determination unit 12, a mode selection unit 13, a signal processing circuit 14, and a communication unit 15. The communication unit 15 includes a VHF communication circuit 16, an LTE communication circuit 17, and a GNSS (Global Navigation Satellite System) communication circuit 18. The radio station 1 includes antennas 31, 32, 33 corresponding to the VHF communication circuit 16, the LTE communication circuit 17, and the GNSS communication circuit 18 respectively, an operation unit 51, and an input unit 52.

[0028] In FIG. 2, only the transmission function of the radio station 1 is shown, but the radio station 1 may have a reception function as shown in FIG. 3. The radio station 1 shown in FIG. 3 includes a detector 19 and an output unit 53 in addition to the configuration of the radio station 1 shown in FIG. 2. The signal processing circuit 14 includes a transmission signal processing circuit 20 on the transmission side and a reception signal processing circuit 21 on the reception side.

[0029] As shown in FIG. 4, as an example of the hardware configuration for controlling each unit, the radio station 1 includes a processor 81, a memory 82, and an interface 83. The processor 81, the memory 82, and the interface 83 are connected to each other by a bus 80. Each function in the radio station 1 is realized by the processor 81 executing a program stored in the memory 82.

[0030] For example, the interface 83 is for connecting the radio station 1 to other communication devices, specifically, each of the LTE communication device 201 and the VHF communication device 202, and establishing communication. Specifically, the radio station 1 is connected to the public switched telephone network to which the LTE communication device 201 is connected and the VHF communication device 202 via the interface 83. The interface 83 has a plurality of types of interface modules as required.

[0031] In the example of FIG. 4, the radio station 1 has one processor 81 and one memory 82 each, but the radio station 1 may have a plurality of processors 81 and a plurality of memories 82. In this case, each function in the radio station 1 may be executed by the cooperation of the plurality of processors 81 and the plurality of memories 82.

[0032] As another example, as shown in FIG. 5, the radio station 1 may include a processing circuit 84 and an interface circuit 85 as a hardware configuration for controlling each part. The processing circuit 84 is connected to other communication devices via the interface circuit 85. Specifically, the radio station 1 is connected to a public switched telephone network to which the LTE communication device 201 is connected and the VHF communication device 202 via the interface circuit 85.

[0033] When the processing circuit 84 is dedicated hardware, the processing circuit 84 has, for example, a single circuit, a composite circuit, a processor, an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or a combination thereof. Each part of the radio station 1 may be realized by an individual processing circuit 84, or each part of the radio station 1 may be realized by a common processing circuit 84.

[0034] A part of each function of the radio station 1 may be realized by dedicated hardware, and another part may be realized by software or firmware. As shown in FIG. 6, for example, the switching instruction reception unit 11, the position determination unit 12, the mode selection unit 13, and the signal processing circuit 14 are realized by a CPU (Central Processing Unit) 91. The VHF communication circuit 16 is realized by an analog circuit 92, and the LTE communication circuit 17 and the GNSS communication circuit 18 are realized by an LTE module 93. At this time, the GNSS communication circuit 18 is realized by a GNSS module built in the LTE module 93. Note that the GNSS communication circuit 18 may be realized by a GNSS unit independent of the LTE module 93. The detector 19 is realized by a DSP (Digital Signal Processor) 94.

[0035] The switching instruction reception unit 11 receives an instruction from the operation unit 51 to switch between the transmission mode and the reception mode of the radio station 1. The operation unit 51 preferably has a PTT switch, which is a single operation switch that switches between the transmission mode and the reception mode by mechanical operation.

[0036] Specifically, when the PTT switch is pressed, the switching instruction reception unit 11 receives an instruction to switch from the reception mode to the transmission mode. When the switching instruction reception unit 11 receives an instruction to switch from the reception mode to the transmission mode, it notifies the mode selection unit 13 that it has received an instruction to switch from the reception mode to the transmission mode.

[0037] When the PTT switch is no longer pressed, the switching instruction reception unit 11 receives an instruction to switch from the transmission mode to the reception mode. When the switching instruction reception unit 11 receives an instruction to switch from the transmission mode to the reception mode, it notifies the reception signal processing circuit 21 that it has received an instruction to switch from the transmission mode to the reception mode.

[0038] The position determination unit 12 determines whether the radio station 1 is located inside the area 101 based on the position information of the radio station 1 obtained from the GNSS communication circuit 18 of the communication unit 15. It is assumed that the position determination unit 12 holds information about a predetermined area 101, specifically, information about the latitude and longitude of the center position of the area 101 and the radius of the area 101. The position determination unit 12 determines whether the radio station 1 is located inside the area 101, for example, based on the position information indicated by the RMC (Recommended Minimum specific) data output from the GNSS communication circuit 18. The position determination unit 12 outputs the determination result to the mode selection unit 13.

[0039] When the switching instruction receiving unit 11 receives an instruction to switch from the reception mode to the transmission mode, the mode selecting unit 13 selects a communication mode in accordance with the determination result of the position determining unit 12. In detail, when the mode selecting unit 13 is notified by the switching instruction receiving unit 11 that the instruction to switch from the reception mode to the transmission mode has been received, the mode selecting unit 13 starts the mode selection process shown in FIG.

[0040] When the determination result acquired from the position determination unit 12 indicates that the wireless station 1 is located inside the area 101 (step S11; Yes), the mode selection unit 13 selects the first communication mode (step S12). For example, the first communication mode associated with the area 101 is a communication mode conforming to the communication standard of the public line, specifically, a communication mode for performing LTE communication.

[0041] When the determination result acquired from the position determination unit 12 indicates that the wireless station 1 is not located inside the area 101 (step S11; No), the mode selection unit 13 selects the second communication mode (step S13). For example, the second communication mode is a communication mode for performing analog wireless communication using the international VHF band as the frequency band.

[0042] When the processing of step S12 or step S13 is completed, the mode selection unit 13 terminates the mode selection processing. The mode selection unit 13 outputs the first communication mode selected in step S12 or the second communication mode selected in step S13 to the transmission signal processing circuit 20 included in the signal processing circuit 14.

[0043] 6 acquires the communication mode selected from the mode selection unit 13, and generates, from the input signal, transmission data corresponding to the first communication mode or the second communication mode selected by the mode selection unit 13. In detail, the transmission signal processing circuit 20 performs signal processing corresponding to the first communication mode or the second communication mode on an audio signal that is input from an input unit 52 having a microphone, for example, and A / D converted by an A / D (Analog / Digital) converter (not shown), to generate transmission data.

[0044] Specifically, when the communication mode acquired from the mode selection unit 13 is the first communication mode for performing LTE communication, the transmission signal processing circuit 20 generates voice packets from the voice signal and outputs the generated voice packets to the LTE communication circuit 17. When the communication mode selected from the mode selection unit 13 is the second communication mode for performing international VHF communication, the transmission signal processing circuit 20 performs modulation processing on the voice signal to generate a modulation signal, and outputs the generated modulation signal to the VHF communication circuit 16. It is assumed that the transmission signal processing circuit 20 holds in advance information about the operating frequency bands and communication standards corresponding to each of the first communication mode and the second communication mode.

[0045] The communication unit 15 communicates with other communication devices, specifically, the LTE communication device 201 and the VHF communication device 202 shown in FIG. 1, and GNSS satellites (not shown). When the radio station 1 is in the transmission mode, the communication unit 15 shown in FIG. 6 generates a transmission signal from the transmission data generated by the transmission signal processing circuit 20, specifically, the modulation signal or the voice packet, and transmits the transmission signal.

[0046] Specifically, the VHF communication circuit 16 performs signal processing such as frequency conversion, filtering, and amplification on the modulation signal acquired from the transmission signal processing circuit 20 via a D / A (Digital / Analog) converter (not shown) to generate a transmission signal. The VHF communication circuit 16 outputs the transmission signal to a predetermined channel, for example, a calling / response channel, via the antenna 31. Thereafter, when the VHF communication device 202 responds, communication between the radio station 1 and the VHF communication device 202 becomes possible.

[0047] The LTE communication circuit 17 performs signal processing such as modulation, frequency conversion, filtering, and amplification on the voice packet acquired from the transmission signal processing circuit 20 to generate a transmission signal. The LTE communication circuit 17 sends the generated transmission signal to the LTE communication device 201, which is the destination associated with the area 101, via the antenna 32.

[0048] The communication unit 15 receives signals in each used frequency band of the communication mode. Specifically, the communication unit 15 receives signals in the 150 MHz band, which is the used frequency band for international VHF communication, and the used frequency band for LTE communication, for example, the 800 MHz band.

[0049] The VHF communication circuit 16 performs signal processing such as frequency conversion, filtering, and amplification on the electrical signal obtained from the antenna 31 that generates an electrical signal based on the captured radio wave to generate a received signal. The VHF communication circuit 16 outputs the generated received signal to the detector 19.

[0050] The LTE communication circuit 17 performs signal processing such as frequency conversion, filtering, amplification, and demodulation on the electrical signal obtained from the antenna 32 that generates an electrical signal based on the captured radio wave to generate an audio packet. The LTE communication circuit 17 outputs the audio packet to the received signal processing circuit 21.

[0051] The GNSS communication circuit 18 captures radio waves transmitted from GNSS satellites and performs signal processing such as frequency conversion, filtering, and amplification on the electrical signal obtained from the antenna 33 that generates an electrical signal based on the captured radio wave to extract position information. The GNSS communication circuit 18 outputs the position information to the position determination unit 12.

[0052] The detector 19 detects the received signal to generate a demodulated signal and outputs the demodulated signal to the received signal processing circuit 21.

[0053] When the received signal processing circuit 21 acquires the demodulated signal from the detector 19, it outputs the demodulated signal to the output unit 53 via a D / A converter (not shown). When the received signal processing circuit 21 acquires an audio packet from the LTE communication circuit 17, it generates an audio signal from the audio packet and outputs the audio signal to the output unit 53 via a D / A converter.

[0054] The output unit 53 has, for example, a speaker. The output unit 53 outputs the analog audio signal acquired from the received signal processing circuit 21 via the D / A converter from the speaker.

[0055] As shown in FIG. 1, the wireless station 1 having the above configuration is located inside or outside the area 101. The wireless station 1 located inside the area 101 is distinguished as the wireless station 1a, and the wireless station 1 located outside the area 101 is distinguished as the wireless station 1b.

[0056] Since the mode selection unit 13 provided in the wireless station 1a is located inside the area 101, it selects the first communication mode for performing LTE communication. As a result, the wireless station 1a communicates with the LTE communication device 201. Since the mode selection unit 13 provided in the wireless station 1b is located outside the area 101, it selects the second communication mode for performing international VHF communication. As a result, the wireless station 1b communicates with the VHF communication device 202.

[0057] As described above, when the wireless station 1 according to the first embodiment receives an instruction to switch from the reception mode to the transmission mode, it transmits a transmission signal corresponding to the first communication mode for performing LTE communication or the second communication mode for performing international VHF communication according to whether the wireless station 1 is located inside the area 101. Since the wireless station 1 automatically switches the communication mode according to whether its own device is located inside the area 101, it does not require a PTT switch for each frequency, and the configuration is simple.

[0058] The wireless station 1 according to the first embodiment can be variously modified in addition to the above description. First, the wireless station 1 may display on the display screen whether the wireless station 1 is located inside the area 101. The wireless station 2 shown in FIG. 8 further includes an output control unit 22 in addition to the configuration of the wireless station 1. The output control unit 22 is realized by the CPU 91. The GNSS communication circuit 18 is realized by the GNSS unit 95. The output unit 53 has a speaker and a display screen. The output control unit 22 acquires the discrimination result from the position discrimination unit 12. The output control unit 22 controls the output unit 53 to display the discrimination result of the position discrimination unit 12 on the display screen included in the output unit 53.

[0059] Specifically, when the position determination unit 12 determines that the radio station 2 is located inside the area 101, the output control unit 22 causes the display screen of the output unit 53 to display that communication in the first mode, for example, LTE communication, is possible. When the position determination unit 12 determines that the radio station 2 is located outside the area 101, the output control unit 22 causes the display screen of the output unit 53 to display that communication in the second mode, for example, international VHF communication, is possible.

[0060] Second, the radio station 1 may receive an instruction to switch between the transmission mode and the reception mode according to the presence or absence of an input signal, regardless of the operation of the PTT switch. The switching instruction reception unit 11 provided in the radio station 3 shown in FIG. 9 receives an instruction to switch from the reception mode to the transmission mode when the input unit 52 detects the input of voice. The switching instruction reception unit 11 receives an instruction to switch from the transmission mode to the reception mode when the input of voice can no longer be detected from the state where voice is being input to the input unit 52.

[0061] Third, the communication mode of the radio station 1 is not limited to the above example. For example, the radio station 4 shown in FIG. 10 communicates in either a communication mode for performing LTE communication or a communication mode for performing digital wireless communication using a frequency band assigned to business wireless communication as the used frequency band. The communication unit 15 provided in the radio station 4 has a business wireless communication circuit 23. The radio station 4 includes an antenna 34 corresponding to the business wireless communication circuit 23. When the mode selection unit 13 provided in the radio station 4 receives an instruction to switch from the reception mode to the transmission mode by the switching instruction reception unit 11, the first communication mode for performing LTE communication is selected when the radio station 4 is located inside the area 101, and the second communication mode for performing business wireless communication is selected when the radio station 4 is located outside the area 101.

[0062] When the second communication mode is selected by the mode selection unit 13, the transmission signal processing circuit 20 performs modulation processing on the audio signal to generate a modulated signal, and outputs the generated modulated signal to the commercial wireless communication circuit 23. The commercial wireless communication circuit 23 generates a transmission signal by performing signal processing such as frequency conversion, filtering, and amplification on the modulated signal obtained from the transmission signal processing circuit 20 via a D / A converter (not shown). The commercial wireless communication circuit 23 outputs the transmission signal to a predetermined channel via an antenna 34.

[0063] The commercial wireless communication circuit 23 generates a received signal by performing signal processing such as frequency conversion, filtering, and amplification on the electrical signal acquired from the antenna 34, which generates an electrical signal based on the captured radio waves. The commercial wireless communication circuit 23 outputs the generated received signal to the detector 19.

[0064] The detector 19 detects the received signal acquired from the business wireless communication circuit 23, generates a demodulated signal, and outputs the demodulated signal to the received signal processing circuit 21. When the received signal processing circuit 21 acquires the demodulated signal from the detector 19, it outputs the demodulated signal to the output unit 53 via a D / A converter (not shown).

[0065] Fourth, the number of areas 101 is not limited to one, and multiple areas can be set. As shown in FIG. 11, areas 101 and 102 may be set, each associated with a first communication mode for performing LTE communication. In other words, the multiple areas determined by the location determination unit 12, specifically, the first communication mode corresponding to each of the areas 101 and 102, use the same frequency band and communication standard. In this case, a communication mode for performing international VHF communication is set as the second communication mode. A wireless station 1 located within the area 101 is designated as wireless station 1a, a wireless station 1 located within the area 102 is designated as wireless station 1c, and a wireless station 1 located neither within the area 101 nor within the area 102, i.e., located outside both the area 101 and the area 102, is designated as wireless station 1b.

[0066] The position determination unit 12 provided in the wireless stations 1a - 1c determines whether the wireless station 1 is located inside any of the plurality of regions 101 and 102.

[0067] When the mode selection unit 13 provided in the wireless station 1a receives an instruction to switch from the reception mode to the transmission mode at the switching instruction reception unit 11, since the wireless station 1a is located inside the region 101, it selects the first communication mode. As a result, the wireless station 1a communicates with the LTE communication device 201. When the mode selection unit 13 provided in the wireless station 1c receives an instruction to switch from the reception mode to the transmission mode at the switching instruction reception unit 11, since the wireless station 1c is located inside the region 102, it selects the first communication mode. As a result, the wireless station 1c communicates with the LTE communication device 201. When the mode selection unit 13 provided in the wireless station 1b receives an instruction to switch from the reception mode to the transmission mode at the switching instruction reception unit 11, since the wireless station 1b is located outside the regions 101 and 102, it selects the second communication mode. As a result, the wireless station 1b communicates with the VHF communication device 202.

[0068] Among all the communication modes in which the wireless station 1 can communicate, the communication mode corresponding to at least one region may be different from the communication mode corresponding to other regions. Specifically, at least either the frequency band and communication standard of the first communication mode corresponding to the regions 101 and 102 may be different from each other. As shown in FIG. 12, a region 101 associated with the first communication mode for performing LTE communication and a region 103 associated with the first communication mode for performing business wireless communication may be set. At this time, as the second communication mode, a communication mode for performing international VHF communication is set. The wireless station 5 located inside the region 101 is designated as the wireless station 5a, the wireless station 5 located inside the region 103 is designated as the wireless station 5c, and the wireless station 5 that is not located inside either of the regions 101 and 103, that is, the wireless station 5 located outside the region 101 and outside the region 103 is designated as the wireless station 5b.

[0069] As shown in FIG. 13, in addition to the configuration of the wireless station 1, the wireless station 5 further includes a business-use wireless communication circuit 23 and an antenna 34. The configurations and operations of the business-use wireless communication circuit 23 and the antenna 34 are the same as those of the business-use wireless communication circuit 23 and the antenna 34 included in the communication unit 15 of the wireless station 4 shown in FIG. 10. The detector 19 included in the wireless station 5 operates in the same manner as the detector 19 included in the wireless stations 1 and 4.

[0070] The operations of the wireless stations 5a and 5b are the same as those of the wireless stations 1a and 1b shown in FIG. 11. The operation of the wireless station 5c is the same as that of the wireless station 4 shown in FIG. 10. Specifically, when the mode selection unit 13 included in the wireless station 5c receives an instruction to switch from the reception mode to the transmission mode at the switching instruction reception unit 11, since the wireless station 5c is located inside the area 103, it selects the first communication mode for performing business-use wireless communication. As a result, the wireless station 5c communicates with the business-use wireless communication device 203.

[0071] Fifthly, the mode selection process by the mode selection unit 13 is not limited to the above example. As an example, the mode selection unit 13 may determine whether the position information is valid. Specifically, when the mode selection unit 13 receives an instruction to switch from the reception mode to the transmission mode, it starts the mode selection process shown in FIG. 14. The mode selection unit 13 determines whether the position information obtained from the GNSS communication circuit 18 is valid (step S21). Specifically, the mode selection unit 13 determines whether the position information is valid based on whether the RMC data obtained from the GNSS communication circuit 18 is in a specified format, whether the value of the position information indicated by the RMC data is within a predetermined range, etc.

[0072] When the position information is valid (step S21; Yes), the mode selection unit 13 performs the processes after step S11 in the same manner as in the first embodiment. When the position information is not valid, in other words, when the position information is invalid (step S21; No), the mode selection unit 13 selects the second communication mode (step S13). Thereby, while valid position information cannot be obtained, the wireless station 1 can communicate in the second communication mode corresponding to the outside of the area 101.

[0073] Sixth, the position determination unit 12 may determine whether the wireless station 1 is located inside the area 101, 102, 103 based on other information, not limited to the position information acquired from the GNSS communication circuit 18. As an example, when the area 101 is associated with a first communication mode in which LTE communication is performed, the position determination unit 12 may determine whether the wireless station 1 is located inside the area 101 based on whether the LTE communication circuit 17 is able to communicate with a base station for LTE communication.

[0074] Seventh, the communication modes corresponding to the areas 101, 102, and 103 can be determined arbitrarily. As an example, international VHF communication may be set as the first communication mode corresponding to the area 101, and LTE communication may be set as the second communication mode. The area 101 is preferably included in an area where analog wireless communication using the international VHF band is possible. In this case, when the wireless station 1a is switched from the reception mode to the transmission mode, the mode selection unit 13 included in the wireless station 1a selects the first communication mode for performing international VHF communication. When the wireless station 1b is switched from the reception mode to the transmission mode, the mode selection unit 13 included in the wireless station 1b selects the second communication mode for performing LTE communication.

[0075] (Embodiment 2) The method of switching communication modes is not limited to the above example. Fig. 15 shows a wireless station 6 that switches communication modes depending on a received signal as well as the determination result of whether or not the wireless station 6 is located inside an area 101. In the example of Fig. 15, one area 101 is defined that corresponds to a first communication mode for performing LTE communication. At this time, a communication mode for performing international VHF communication is set as a second communication mode. In Fig. 15, a wireless station 6 located inside the area 101 is designated as wireless station 6a, and a wireless station 6 located outside the area 101 is designated as wireless station 6b.

[0076] The radio station 6a communicates with the LTE communication device 201 using LTE communication. The radio station 6b communicates with the VHF communication device 202 using international VHF communication. When the radio station 6a receives an instruction to switch from the receive mode to the transmit mode, if the radio station 6a has received a signal from the VHF communication device 202 or the radio station 6b within the target period, which is the most recent specified period, the radio station 6a communicates with the VHF communication device 202 or the radio station 6b using international VHF communication. This function is called the talkback function. The length of the target period can be set arbitrarily. In the radio station 6, the talkback function can be switched on and off by operating the operation unit 51.

[0077] As shown in FIG. 16 , the radio station 6 further includes a signal detection unit 24 in addition to the components of the radio station 1. The signal detection unit 24 is implemented by the CPU 91. The signal detection unit 24 determines whether a signal in the frequency band used in the second communication mode is being received, i.e., whether a signal in the international VHF band is being received. Specifically, the signal detection unit 24 determines whether the signal level of the modulated signal output by the detector 19 is equal to or greater than a threshold. If the signal level of the modulated signal is equal to or greater than the threshold, it can be determined that the VHF communication circuit 16 is receiving a signal. The threshold may be set to a value that allows it to be determined that the VHF communication circuit 16 is receiving a signal, depending on the minimum value that the signal level of the modulated signal can take when the VHF communication circuit 16 is receiving a signal. The signal detection unit 24 outputs the determination result to the mode selection unit 13.

[0078] When the switching instruction receiving unit 11 receives an instruction to switch from the reception mode to the transmission mode, the mode selecting unit 13 selects a communication mode in accordance with the discrimination results of the position determining unit 12 and the discrimination results of the signal detecting unit 24. In detail, when the mode selecting unit 13 is notified by the switching instruction receiving unit 11 that the instruction to switch from the reception mode to the transmission mode has been received, the mode selecting unit 13 starts the mode selection process shown in Fig. 17. The processes of steps S11, S12, and S13 shown in Fig. 17 are the same as the processes of steps S11, S12, and S13 shown in Fig. 7.

[0079] When the determination result obtained from the position determination unit 12 indicates that the wireless station 1 is located inside the area 101 (step S11; Yes) and the determination result obtained from the signal detection unit 24 indicates that no signal has been received in the frequency band used in the second communication mode during the target period (step S31; No), the mode selection unit 13 selects the first communication mode for performing LTE communication (step S12).

[0080] If the determination result obtained from the position determination unit 12 indicates that the wireless station 1 is located inside the area 101 (step S11; Yes) and the determination result obtained from the signal detection unit 24 indicates that a signal is being received in the frequency band used in the second communication mode during the target period (step S31; Yes), but the talkback function is off (step S32; No), the mode selection unit 13 selects the first communication mode for performing LTE communication (step S12).

[0081] If the determination result obtained from the position determination unit 12 indicates that the radio station 1 is located inside the area 101 (step S11; Yes), if the determination result obtained from the signal detection unit 24 indicates that a signal is being received in the frequency band used in the second communication mode during the target period (step S31; Yes), and if the talkback function is on (step S32; Yes), the mode selection unit 13 selects the second communication mode for performing international VHF communication (step S13).

[0082] When the processing of step S12 or step S13 is completed, the mode selection unit 13 terminates the mode selection processing. The mode selection unit 13 outputs the first communication mode selected in step S12 or the second communication mode selected in step S13 to the transmission signal processing circuit 20 included in the signal processing circuit 14.

[0083] The mode selection unit 13 provided in the wireless station 6a shown in FIG. 15 receives an instruction to switch from the reception mode to the transmission mode at the switching instruction reception unit 11, and when no signal in the frequency band of the second communication mode has been received during the target period, selects the first communication mode. As a result, the wireless station 6a communicates with the LTE communication device 201. The mode selection unit 13 provided in the wireless station 6a receives an instruction to switch from the reception mode to the transmission mode at the switching instruction reception unit 11, and when a signal in the frequency band of the second communication mode has been received during the target period, selects the second communication mode. As a result, the wireless station 6a communicates with the VHF communication device 202 or the wireless station 6b.

[0084] As described above, when the wireless station 6 according to Embodiment 2 receives an instruction to switch from the reception mode to the transmission mode, if the wireless station 6 is located inside the area 101 and a signal is received in the frequency band of the second communication mode during the target period, communication is performed in the second communication mode. When the wireless station 6 receives an instruction to switch from the reception mode to the transmission mode, if the wireless station 6 is located inside the area 101 and no signal is received in the frequency band of the second communication mode during the target period, communication is performed in the first communication mode.

[0085] Thereby, while the wireless station 6a located inside the area 101 is not receiving a signal from the VHF communication device 202 or the wireless station 6b located outside the area 101, it communicates with the LTE communication device 201, and when it receives a signal from the VHF communication device 202 or the wireless station 6b, it can automatically switch the communication mode and communicate with the VHF communication device 202 or the wireless station 6b.

[0086] The wireless station 6 according to Embodiment 2 can be variously modified in addition to what has been described above. First, the talkback function may be enabled even when the wireless station 6 is located outside the area 101. In this case, the signal detection unit 24 determines whether the signal is being received in the frequency band used in the first communication mode or the second communication mode, and outputs the determination result. In detail, if the signal level of the modulated signal output by the detector 19 is equal to or higher than a threshold, the signal detection unit 24 determines that the signal is being received in the frequency band used in the second communication mode. When the signal detection unit 24 acquires a voice packet from the LTE communication circuit 17, it determines that the signal is being received in the frequency band used in the first communication mode.

[0087] When the mode selection unit 13 is notified by the switching instruction receiving unit 11 that an instruction to switch from the reception mode to the transmission mode has been received, the mode selection unit 13 starts the mode selection process shown in Fig. 18. The processes of steps S11-S13, S31, and S32 shown in Fig. 18 are the same as the processes of steps S11-S13, S31, and S32 shown in Fig. 17.

[0088] When the determination result obtained from the position determination unit 12 indicates that the wireless station 1 is located outside the area 101 (step S11; No) and the determination result obtained from the signal detection unit 24 indicates that no signal has been received in the frequency band used in the first communication mode during the target period (step S33; No), the mode selection unit 13 selects the second communication mode for performing international VHF communication (step S13).

[0089] If the determination result obtained from the position determination unit 12 indicates that the radio station 1 is located outside the area 101 (step S11; No), and the determination result obtained from the signal detection unit 24 indicates that a signal is being received in the frequency band used in the first communication mode during the target period (step S33; Yes), but the talkback function is off (step S34; No), the mode selection unit 13 selects the second communication mode for performing international VHF communication (step S13).

[0090] When the determination result obtained from the position determination unit 12 indicates that the wireless station 1 is located outside the area 101 (step S11; No), the determination result obtained from the signal detection unit 24 indicates that a signal is being received in the frequency band used in the first communication mode during the target period (step S33; Yes), and the talkback function is on (step S34; Yes), the mode selection unit 13 selects the first communication mode for performing LTE communication (step S12).

[0091] Second, the talkback function may be set to always on. In this case, the operation unit 51 does not need to have a function for switching the talkback function on and off. The modifications described in the first embodiment can also be applied to the second embodiment.

[0092] Furthermore, the above-described hardware configuration and flowchart are merely examples and can be changed and modified as desired. [Explanation of symbols]

[0093] 1,1a,1b,1c,2,3,4, 5,5a,5b,5c,6,6a,6b Radio station 11 Switching instruction reception unit 12 Position determination section 13 Mode selection section 14 Signal processing circuit 15 Communications Department 16 VHF communication circuit 17 LTE communication circuit 18 GNSS communication circuit 19 Detector 20 Transmission signal processing circuit 21 Received signal processing circuit 22 Output control section 23 Commercial wireless communication circuit 24 Signal detection unit 31, 32, 33, 34 Antenna 51 Operation section 52 Input section 53 Output section 80 Bus 81 processors 82 memory 83 Interface 84 Processing Circuit 85 Interface Circuit 91 CPU 92 Analog Circuits 93 LTE module 94 DSP 95 GNSS units 101,102,103 area 201 LTE communication equipment 202 VHF communication equipment 203 Commercial wireless communication equipment

Claims

1. A wireless station that communicates in a plurality of communication modes in which at least one of the used frequency bands and communication standards is different from each other, a position determination unit that determines whether or not the wireless station is located inside any one of at least one predetermined area indicating a geographical range associated with any one of the communication modes, a switching instruction reception unit that receives an instruction to switch between the transmission mode and the reception mode of the wireless station, when the switching instruction reception unit receives an instruction to switch to the transmission mode, if the position determination unit determines that the wireless station is located inside the area, among the plurality of communication modes, a first communication mode corresponding to the area where the wireless station is located is selected, and if the position determination unit determines that the wireless station is not located inside any of the areas, a second communication mode, which is a communication mode different from the first communication mode, is selected; a mode selection unit, a signal processing circuit that generates transmission data corresponding to the first communication mode or the second communication mode selected by the mode selection unit from an input signal, a communication unit that generates a transmission signal from the transmission data generated by the signal processing circuit and transmits the transmission signal, A wireless station comprising:

2. The communication unit receives signals in the respective used frequency bands of the communication modes, when the switching instruction reception unit receives an instruction to switch to the transmission mode and the position determination unit determines that the wireless station is located inside the area, if the communication unit has received a signal in the used frequency band of the second communication mode during a target period, which is a recently defined period, the second communication mode is selected, and if the communication unit has not received a signal in the used frequency band of the second communication mode during the target period, the first communication mode is selected. The wireless station according to claim 1. The wireless station according to claim 1.

3. when the switching instruction reception unit receives an instruction to switch to the transmission mode and the position determination unit determines that the wireless station is not located inside any of the areas, if the communication unit has received a signal in the used frequency band of the first communication mode during the target period, the first communication mode is selected, and if the communication unit has not received a signal in the used frequency band of the first communication mode during the target period, the second communication mode is selected. The wireless station according to claim 1. The wireless station according to claim 2.

4. When the mode selection unit receives an instruction to switch to the transmission mode from the switching instruction receiving unit and it is determined by the position determination unit that the wireless station is located inside the area, the first communication mode compliant with the communication standard of the public line is selected. The wireless station according to claim 1 or 2.

5. The position determination unit determines whether the wireless station is located inside the area included in the area where the public line can be connected. The wireless station according to claim 4.

6. When the mode selection unit receives an instruction to switch to the transmission mode from the switching instruction receiving unit and it is determined by the position determination unit that the wireless station is not located inside any of the areas, the second communication mode that performs analog wireless communication using the international VHF (Very High Frequency) band as the used frequency band is selected. The wireless station according to claim 4.

7. When the mode selection unit receives an instruction to switch to the transmission mode from the switching instruction receiving unit and it is determined by the position determination unit that the wireless station is not located inside any of the areas, the second communication mode that performs digital wireless communication using the frequency band assigned to business wireless communication as the used frequency band is selected. The wireless station according to claim 4.

8. When the mode selection unit receives an instruction to switch to the transmission mode from the switching instruction receiving unit and it is determined by the position determination unit that the wireless station is located inside the area, the first communication mode that performs analog wireless communication using the international VHF band as the used frequency band is selected. The wireless station according to claim 1 or 2.

9. The position determination unit determines whether the wireless station is located inside the area included in the area where analog wireless communication using the international VHF band is possible. The wireless station according to claim 8.

10. When the mode selection unit receives an instruction to switch to the transmission mode from the switching instruction receiving unit and it is determined by the position determination unit that the wireless station is not located inside any of the areas, the second communication mode compliant with the communication standard of the public line is selected. The wireless station according to claim 8.

11. The switching instruction receiving unit receives an instruction to switch between the transmission mode and the reception mode from a single operation switch that switches between the transmission mode and the reception mode by a mechanical operation. The wireless station according to claim 1 or 2.

12. The position determination unit determines whether the wireless station is located inside any of the plurality of regions for the plurality of regions. The wireless station according to claim 1 or 2.

13. The operating frequency bands and the communication standards of the first communication mode corresponding to each of the regions are the same as each other. The wireless station according to claim 12.

14. At least one of the operating frequency band and the communication standard of the first communication mode corresponding to at least one of the regions is different from the operating frequency band and the communication standard of the first communication mode corresponding to the other regions. The wireless station according to claim 12.

15. A communication method performed by a wireless station that communicates in a plurality of communication modes in which at least one of an operating frequency band and a communication standard is different from each other, determining whether the wireless station is located inside any of at least one predetermined region indicating a geographical range associated with any of the communication modes, receiving an instruction to switch between the transmission mode and the reception mode of the wireless station, when receiving an instruction to switch to the transmission mode, if the wireless station is determined to be located inside the region, selecting a first communication mode corresponding to the region where the wireless station is located from among the plurality of communication modes, and if the wireless station is determined not to be located inside any of the regions, selecting a second communication mode that is a communication mode different from the first communication mode, generating transmission data corresponding to the selected first communication mode or the second communication mode from an input signal, generating a transmission signal from the transmission data and transmitting the transmission signal. Communication method.

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