JP6158650B2 - Wireless communication system - Google Patents

Description

  The present invention relates to a wireless communication system.

  A wireless communication system that performs wireless communication between a master station and a slave station is known. For example, a transmission wave transmitted from a master station is received by a fixed wireless terminal device or a movable wireless terminal device.

  Conventionally, a technique of a wireless communication system that can perform wireless communication using an appropriate frequency band without bothering the operator of the communication device has been disclosed (for example, see Patent Document 1).

JP 2010-206759 A

By the way, not only a system to which a dedicated frequency (channel) is assigned but also a system in which an unspecified number of users share a plurality of frequencies in the wireless communication system. In such a system, there is a possibility that another system is using the frequency used by the base station, or there is a possibility that an interference wave exists. Therefore, the base station may determine the interference wave. However, since the determination of the interference wave by the base station depends on the reception performance of the base station, it is difficult to determine the radio wave environment of a wireless communication terminal (hereinafter also referred to as a slave station) installed at the end of the communication area. For example, an interference wave that cannot be received by the base station may exist at the end of the communication area of the base station, and the communication quality of the slave station at the end of the communication area may not be ensured.
The present invention has been made in view of such problems, and an object of the present invention is to detect a jamming wave with high accuracy so that communication can be performed on a channel with little influence of the jamming wave.

  A radio communication system according to the present invention includes a master station, a base station radio communication device connected to the master station, and a plurality of radio communication terminals that receive signals transmitted from the base station radio communication device through a radio channel. A wireless communication system comprising: a master station and a wireless communication terminal configured to be connected and transmitted / received by a separate line different from the wireless line, wherein the master station is connected to the wireless communication terminal via the separate line; An instruction signal instructing channel scanning of the wireless line is transmitted, and when the wireless communication terminal receives the instruction signal on the separate line, the wireless communication terminal executes a channel scan related to the wireless line, and results information on the result is sent to the separate line. And when the master station receives the result information through the separate line, the base station determines a channel to be used by the base station radio communication apparatus based on the result information.

  In the above wireless communication system, when the base station transmits a broadcast from the base station wireless communication device to the wireless communication terminal using the wireless line, the master station transmits an instruction signal through another line, and the result information from the wireless communication terminal Based on the above, the channel of the base station wireless communication device used for broadcasting is determined.

  Furthermore, in the above-described wireless communication system, when the wireless communication terminal receives the instruction signal, it measures the received electric field strength of each of a plurality of preset channels or a plurality of channels designated by the instruction signal as a channel scan. The information on the measurement result is transmitted to the master station as result information.

  According to the present invention, since the master station can collect the radio wave environment information around the wireless communication terminal, it is possible to accurately detect the interference wave and communicate with the slave station through a channel with little influence of the interference wave.

1 is a block diagram of a wireless communication system according to an embodiment of the present invention. 1 is a block diagram of a slave station and a wireless device of a wireless communication system according to an embodiment of the present invention. It is a sequence diagram of the radio | wireless communications system which concerns on one Example of this invention.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram of a wireless communication system (hereinafter referred to as the present wireless communication system) according to an embodiment of the present invention.
As shown in FIG. 1, the wireless communication system includes a broadcast console 102 and a control device 103 which are a master station 100, a first base station wireless communication device for broadcasting (hereinafter also referred to as a first base station) 101, , A second base station wireless communication apparatus (hereinafter also referred to as a second base station) 110 for collecting information and slave stations 121 to 125 which are wireless communication terminals. In FIG. 1, wireless devices 131 and 141 are wireless terminals of other wireless communication systems.
The wireless communication system is a broadcast wireless system, such as a district broadcast (regional promotion) wireless communication system in a 150 MHz band or a 400 MHz band.
In FIG. 1, the communicable area of the base station 101 is a communication area 101a.

The broadcast console 102 is a device for an operator to broadcast to the slave stations 121 to 125, and includes an operation unit, a microphone, and the like (not shown) operated by the operator.
The control device 103 controls the first base station 101 and the second base station 110 based on instructions from the broadcast console 102. That is, the control device 103 controls connection of communication lines of the wireless communication system. Further, when broadcasting from the first base station 101, the control device 103 issues an interference wave detection (channel scan) instruction to the first base station 101 and the preset slave stations 121 to 123, and these first Based on detection results from the base station 101 and the slave station, the frequency (channel; frequency channel) used by the first base station 101 for broadcasting is determined. Note that the preset slave stations 121 to 123 are configured so that the first base station can detect the interference wave more reliably and efficiently based on the channel scan capability (possible area) of the first base station 101, for example. 101 is a slave station 121 to 123 provided at the end of the communication area 101a where it is difficult to detect interference waves, and is preferably selected in consideration of installation balance (predetermined distance interval).

  In the present embodiment, the control device 103 controls both the first base station 101 and the second base station 110, but each of the first base station 101 and the second base station 110 has a dedicated control device 103. It may be done. Also, a broadcasting console 102 for inputting a communication instruction related to the first base station 101 and the second base station 110 to the control device 103 is provided exclusively for the first base station 101 and the second base station 110, respectively. May be.

  The first base station 101 is a base station for transmitting voice and data broadcasts to the slave stations 121 to 125. For example, the first base station 101 wirelessly uses one channel from a plurality of frequency channels of 150 MHz band or 400 MHz band. Send. It is desirable that the first base station 101 holds a plurality of frequency channel candidates to be used among a plurality of frequency channels in advance, and selects and uses one of these candidates. Information on these frequency channel candidates is also stored in advance in the slave stations 121 to 125, so that the slave stations 121 to 125 perform channel scanning for receiving broadcasts from the first base station 101, the number of frequency channel candidates, Alternatively, channel scanning efficiency is improved because only the range needs to be performed.

The second base station 110 transmits and receives information to and from the slave stations 121 to 125. For example, radio environment information (interference wave detection result) from the slave stations 121 to 125 and the reception result of the broadcast from the first base station 101. Collect information. Here, the second base station 110 performs radio communication with the slave stations 121 to 125 using a frequency channel different from the frequency band used by the first base station 101, for example, a frequency channel of 920 MHz band (915 to 930 MHz). .
A relay device may be provided between the second base station 110 and the slave stations 121 to 125.

  The slave stations 121 to 125 are installed in each household, for example, receive at least a broadcast from the first base station 101, and further transmit / receive information to / from the second base station 110. That is, the slave stations 121 to 125 communicate with the master station on another line of the second base station 110 different from the radio line of the first base station 101.

Specifically, as shown in FIG. 2, the slave stations 121 to 125 that are wireless communication terminals include a broadcast wave receiving unit 201, a wireless unit 202, a control unit (for example, CPU: Central Processing Unit) 203, and a speaker 204. A display unit 205 and an operation unit 206.
The broadcast wave receiving unit 201 receives a broadcast wave transmitted from the first base station 101. As described above, the broadcast wave from the first base station 101 is one of a plurality of preset frequency channel candidates, and the broadcast wave receiving unit 201 periodically performs channel processing on the plurality of frequency channel candidates. Scanning is performed, and broadcast waves from the first base station 101 are received.

The radio unit 202 transmits / receives information to / from the second base station 110, and may communicate with the second base station 110 through a preset channel, or may perform channel scanning similar to the broadcast wave receiving unit 201. Thus, communication may be performed by detecting radio waves from the second base station 110.
The control unit 203 performs overall control of the slave stations 121 to 125.
The speaker 204 outputs, for example, broadcast sound received by the broadcast wave receiving unit 201.
The display unit 205 displays broadcast data received by the broadcast wave receiving unit 201, for example.
The operation unit 206 is an interface for the user to adjust the volume of the speaker 204 and to input information to be transmitted via the wireless unit 202.

Next, a sequence when broadcasting from the broadcasting console 102 using the first base station 101 in the wireless communication system will be described with reference to FIG.
When control device 103 receives a broadcast instruction from broadcast console 102, control device 103 preliminarily transmits first base station 101 and a plurality of slave stations 121 to 125 before transmitting the broadcast from first base station 101 based on the instruction. The set slave stations 121 to 123 are caused to execute a channel scan for detecting an interference wave, and radio wave environment information as a result is collected. Specifically, a channel scan instruction is issued to the first base station 101 (300), and a channel scan instruction is issued to the second base station 110 (301).

When receiving the channel scan instruction from the control device 103, the first base station 101 performs channel scanning of broadcast wave frequency channel candidates (here, channels C11 to C14) using its own receiver. Then, the first base station 101 transmits the received electric field strength of each channel as a channel scan result to the control device 103 as radio wave environment information (300a).
In order to collect radio wave environment information from the slave stations 121 to 123, the second base station 110 designates the slave stations 121 to 123 as destinations and issues a channel scan instruction (302). Note that the designation information of the slave stations 121 to 123 may be transmitted from the control device 103 to the second base station 110, or may be preset in the second base station 110.

When the wireless station 202 receives the channel scan instruction, the slave stations 121 to 123 have the frequency channel candidates (here,) of the broadcast wave of the first base station 101 set in advance in its own memory (not shown) by the control unit 203. Then, in order to collect radio wave environment information (interference wave information) of channels C11 to C14, the broadcast wave receiving unit 201 performs channel scanning of these frequency channel candidates. Then, the control unit 203 transmits the received electric field strength of each channel as a channel scan result from the wireless unit 202 to the second base station 110 as radio wave environment information (303, 305, 307). Note that, as a result of the channel scan, a certain amount of received electric field strength has been received and any radio wave has been received. This means that the frequency channel is being used by another system, or the adjacent channel is being used by another system, and the interference wave There will be.
The second base station 110 sequentially transmits the radio wave environment information received from each of the slave stations 121 to 123 to the control device 103 (304, 306, 308).

  Note that the communication between the second base station 110 and each of the slave stations 121 to 123 in the collection of radio wave environment information may be performed after performing a process of establishing a communication line. A polling method may be used, and transmission of the radio wave environment information of each of the slave stations 121 to 123 to the second base station 110 does not collide.

  The channel scans of the slave stations 121 to 123 measure, for example, the received electric field strengths of the broadcast waves C11 to C14, and the broadcast waves C11 to C14 are used by other users in the communication area 100, or these Detect the presence of jamming waves for broadcast waves. For example, as shown in FIG. 1, if the radio wave C21 used by the radio 131 of the other radio communication system is the radio wave C21 having the same frequency as the broadcast waves C11 to C14 or having a frequency close to that of the jamming wave, the slave station 122 Is detected as the received electric field intensity of any one of C11 to C14. Further, if the radio wave C31 used by the radio 141 of the other radio communication system existing outside the communication area 101a is a radio wave having the same frequency as the broadcast waves C11 to C14 or close to the frequency of interference, the communication area 101a is closed. A certain slave station 123 detects the radio wave C31 as the received electric field strength (radio wave environment information) of any one of C11 to C14.

  When the channel scan result is not transmitted from any of the slave stations 121 to 123 that issued the channel scan instruction, the control device 103 forcibly terminates collection of the radio wave environment information after a predetermined time has elapsed. The process may proceed to the next process.

From the collected radio wave environment information of the first base station 101 and the slave stations 121 to 123, the control device 103 determines whether or not there is an interference wave (including use of other systems of the channel itself) and interference of the broadcast waves C11 to C14 due to the interference wave. The degree is determined, and the frequency channel used by the first base station 101 for broadcasting is determined (309).
Here, the priority channel C11 is set in the control device 103 among the plurality of frequency channel candidates C11 to C14. Therefore, the control device 103 first determines the channel scan result for the channel C11. That is, the control apparatus 103 broadcasts the channel C11 if the received electric field strength from the first base station 101 and the slave stations 121 to 123 related to the channel C11 is equal to or lower than a predetermined level (may be 0 dB) that does not affect broadcasting. Decide as a wave.

  However, if any one of the received electric field strengths from the first base station 101 and the slave stations 121 to 123 with respect to the priority channel C11 is larger than the predetermined level, the control device 103 does not adopt the channel C11 and does not adopt other channels. Among the candidates C12 to C14, a channel whose reception electric field strength from the first base station 101 and the slave stations 121 to 123 is a predetermined level or less is determined as a broadcast wave. Here, priorities may be set for the other channel candidates C12 to C14.

  In addition, when the received electric field strength greater than a predetermined level is detected for all frequency channel candidates C11 to C14, the control apparatus 103 again sets the first base station 101 and the slave stations 1211 to 121 for the frequency channel candidates C11 to C14. A channel scan instruction is transmitted to 123 (300, 301), and the above-described processing is repeated until a channel that can be adopted as a broadcast wave is found. Thereby, the broadcast from the 1st base station 101 can be reliably implemented by the broadcast wave without an interference wave.

As another example, in such a case, the control device 103 designates one or a plurality of frequency channels other than the preset frequency channel candidates C11 to C14, and the first base station 101 and the slave stations 121 to 123 are designated. A channel scan instruction may be issued to find a broadcast wave having no interference wave other than the channels C11 to C14. Thereby, broadcasting from the first base station 101 can be performed more quickly.
Then, as shown in FIG. 3, the control device 103 notifies the first base station 101 of the determined broadcast wave (frequency channel) (310) and transmits the broadcast content from the broadcast console 102 (311).

  The first base station 101 transmits a broadcast to the slave stations 121 to 125 using the broadcast wave designated by the control device 103 (312).

  As described above, the control device 103 uses the wireless channel that the first base station 101 uses for broadcasting to the preset slave stations 121 to 123 before transmitting the broadcast from the first base station 101 to the slave stations 121 to 125. An instruction signal for instructing channel scanning is transmitted using a radio channel of the second base station 110, which is a separate channel, and radio wave environment information is collected from the slave stations 121 to 123, and interference occurs without interference. Since a channel that has not been selected is selected as a broadcast wave, high-quality communication can be performed. That is, since the master station can collect radio wave environment information around the slave stations 121 to 123, the master station can detect the interference wave more accurately and can communicate with the slave stations 121 to 125 through a channel with less influence of the interference wave.

  Further, the slave stations 121 to 123 measure the received electric field strengths of a plurality of channels C11 to C14 set in advance or a plurality of channels specified by the instruction signal as channel scans, and provide information on the measurement results. As the result information is transmitted to the second base station 110, as a result, the channel used for broadcasting is broadcast while avoiding interference waves at the end of the communication area 101a that may not be detected by the first base station 101. be able to. Thereby, the broadcast in the communication area 101a can be implemented more reliably and with high quality.

Although the present invention has been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.
For example, in the above-described embodiment, a case where a plurality of frequency channel candidates for channel scanning are registered in advance in the slave stations 121 to 123 has been described as an example. However, it does not have to be registered in advance in the present invention, and includes information specifying the channel to be scanned in the channel scan instruction from the second base station 110, and the slave stations 121 to 123 perform channel scanning based on the information. May be executed. Thereby, since the broadcast wave candidate is not determined in advance, the degree of freedom in selecting the broadcast wave is improved. In addition, it is possible to arbitrarily specify the slave stations 121 to 15 that perform the channel scan.
Further, in the above-described embodiment, the radio channel between the second base station 110 and the radio unit 202 has been described as an example of another channel different from the communication channel of the first base station 101. However, in the present invention, such another line may be wired instead of wireless, and the control device 103 and the slave stations 121 to 123 may be connected via a wired line to transmit and receive information.

  100: master station 101: first base station radio communication device 101a: communication area 102: broadcast console 103: control device 110: second base station radio communication device 121-125: slave station 131 141: Radio unit 201: Broadcast wave receiving unit 202: Radio unit 203: Control unit 204: Speaker 205: Display unit 206: Operation unit C21, C31: Radio wave

Claims (3)

A wireless communication system comprising a parent station, a base station wireless communication device connected to the parent station, and a plurality of wireless communication terminals that receive signals transmitted from the base station wireless communication device through a wireless line,
The master station and the wireless communication terminal are connected by a separate line different from the wireless line, and configured to transmit and receive information,
The master station transmits an instruction signal instructing the wireless communication terminal to perform channel scanning of the wireless line through the separate line,
The wireless communication terminal, when receiving the instruction signal on the separate line, performs a channel scan on the wireless line, and transmits result information on the result to the master station on the separate line,
When the master station receives the result information on the separate line, the base station determines a channel to be used by the base station radio communication device based on the result information. The wireless communication system according to claim 1, wherein
When the master station transmits a broadcast from the base station wireless communication device to the plurality of wireless communication terminals using the wireless line, the base station transmits the instruction signal through the separate line, and the base station wireless communication device transmits the instruction signal from the wireless communication terminal. A wireless communication system, wherein a channel used by the base station wireless communication device used for the broadcast is determined based on result information. The wireless communication system according to claim 1 or 2,
When receiving the instruction signal, the wireless communication terminal measures the received electric field strength of each of a plurality of preset channels or a plurality of channels received together with the instruction signal as a channel scan, and information on the measurement result Is transmitted to the master station as the result information.

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