JP2000101497A - Radio communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a radio communication system, in which a communication time required for relay communication is reduced with high reliability and the system cost, is decreased. SOLUTION: This radio communication system S1 has a plurality of transmission stations ST and a plurality of relay stations and at least one base station SB and is configured, such that transmission data are sent from an optional transmission station ST to the base station SB via one relay station SR or more in a relay communication available way. In this case, each of the relay stations SR that directly receives the transmission data sent from an optional transmission station ST or an arbitrary relay station SR is configured to attain relay communication after the lapse of a prescribed waiting time, after the reception of the transmission data, and mutually differing waiting times are given to the relay stations SR.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio communication system configured so that transmission data can be transmitted from a transmission station to a base station via a relay station.

[0002]

2. Description of the Related Art Generally, as shown in FIG. 7, a radio communication system has one base station SB and a plurality of transmitting stations ST.
1, ST2,... STN (hereinafter, when no distinction is made,
"Transmitting station ST") and a plurality of relay stations SR1, SR
2 ··· SRM (hereinafter, when no distinction is made, “relay station S
R ”). In such a wireless communication system S11, conventionally, transmission data transmitted from the transmission station ST is relayed to the base station SB according to a predetermined communication path.

[0003] In this case, the communication route is determined based on a desk calculation and a field survey. Specifically, in the wireless communication system S11 shown in FIG. 7, when determining a communication path from the transmitting station ST1 to the base station SB, first, the transmitting station S1
A field survey is performed after a range in which the transmission radio wave of T1 reaches is predicted by a desk calculation. In this field survey, the transmitting station ST1 actually transmits a transmission radio wave and investigates the received electric field strength at each of the relay stations SR1 to SR4 installed within the predicted range. Next, the relay station SR closest to the relay station SR and having a sufficient reception field strength for obtaining high reliability is determined as the first relay station. In this example, the relay station SR1 is determined.

[0004] Next, in determining the second relay station SR, similarly, first, a range in which the transmission radio wave of the relay station SR1 reaches is predicted, and the transmission radio wave is actually transmitted from the relay station SR1. The most appropriate relay station SR among the relay stations SR installed within the range set as above is determined as the second relay station SR. In this example, the relay station SR5 is determined. Next, the base station SB performs a site survey on whether or not the transmission radio wave of the relay station SR5 has a sufficient reception electric field strength. When it is determined that the transmission radio wave is sufficient, a communication path for the transmission station ST1 is determined. These operations are performed by other transmitting stations ST2 to ST
N for each communication path. Thereafter, a communication path program is created according to the communication path determined by the field survey, and the communication path program is transmitted to each of the transmitting stations ST.
And incorporated in each relay station SR.

[0005] Relay communication becomes possible only after the above operation is completed. Specifically, in FIG.
When relay communication is performed between T1 and the base station SB, the transmitting station S
T1 transmits transmission data in which the station number of the relay station SR1 is inserted as destination data in accordance with the incorporated communication path program. Next, the relay station SR1 that has received the transmission data transmits the transmission data in which the station number of the relay station SR5 is inserted as the destination data in accordance with the communication path program that is also incorporated. Thereafter, the relay station SR5 transmits the transmission data in which the station number of the base station SB is inserted as the destination data according to the installed communication path program. Thereby, the base station SB can receive the transmission data transmitted by the transmitting station ST1.

Similarly, the transmission data of the transmitting station ST2 is transmitted to the relay station S2 according to the built-in communication path program.
It is transmitted to base station SB via R6, relay station SR7 and relay station SR5. As described above, in the conventional wireless communication system S11, each transmitting station ST and each relay station SR transmit the transmission data in which the destination data is inserted in accordance with the communication path program installed in advance, so that each transmitting station ST transmits the data. The transmitted data is relayed to the base station SB.

[0007]

However, the conventional wireless communication system has the following problems. First
Meanwhile, in the conventional wireless communication system S11, a communication path for relay communication is predetermined. For this reason, when a failure occurs in one relay station SR in the communication path, transmission data cannot be transmitted further. Specifically, in the above example, for example, the relay station SR
5, a transmission data transmitted from the transmitting station ST1 can be relay-communicated to the relay station SR1, but is interrupted between the relay station SR1 and the relay station SR5 to reach the base station SB. Relay communication cannot be performed. If the relay station SR5 is defined as a relay station for another transmitting station ST2, the transmitting station ST5
The transmission data of No. 2 is also disconnected. As described above, the conventional wireless communication system S11 has a problem that the reliability of the entire system is low as a result of the failure of one relay station SR being affected over the entire system.

Second, in the conventional wireless communication system S11, since the communication path is determined uniformly in advance, the communication time required for relay communication from the transmitting station ST to the base station SB is a fixed time. Becomes However, in the desk-top calculation, it is necessary to secure a sufficient reception electric field strength of each relay station SR in order to secure high reliability. For this reason, depending on the relay station SR, it may not be originally targeted by the relay station SR even though a practically sufficient reception electric field strength can be obtained. In addition, actually, due to the arrival of reflected radio waves due to mountain slopes and buildings, and the extension of radio wave reach due to natural phenomena, the relay station SR that was not targeted at the time of desk calculation, In some cases, transmission data can be received with a sufficient reception electric field strength. Specifically, for example, in the above example, the relay station SR4, which is closer to the base station SB than the relay station SR1, has the transmitting station ST4 with a sufficient reception field strength.
One transmission radio wave may be received. In such a case, if relay communication can be performed from the relay station SR4 to the base station SB, the communication time can be reduced. However, the conventional wireless communication system S
11 has no choice but to perform relay communication according to a predetermined communication path. Therefore, the conventional wireless communication system S11
Has a problem that the communication time is long.

Third, in the conventional wireless communication system S11, a desk calculation and a field survey are necessarily required to determine a communication path. Therefore, there is a problem in that the operation up to the determination of the communication path is extremely complicated, and the operation is lengthened, which increases the cost of the communication system.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a radio communication system which has high reliability and can reduce the communication time and system cost for relay communication. Main purpose.

[0011]

According to one aspect of the present invention, there is provided a wireless communication system comprising a plurality of transmitting stations and relay stations, and at least one base station,
In a wireless communication system configured to be able to relay transmission data from an arbitrary transmitting station to a base station via one or more relay stations, directly transmit transmission data transmitted from an arbitrary transmitting station or an arbitrary relay station. Each of the receivable relay stations,
Relay transmission is enabled when a predetermined standby time elapses after receiving transmission data, and different standby times are provided. In this case, the transmitting station,
The relay station and the base station are not fixed concepts, and the transmitting station may function as a relay station, or one of the transmitting station and the relay station may function as a base station.

A wireless communication system according to a second aspect is characterized in that, in the wireless communication system according to the first aspect, the standby time is set to be shorter for a relay station that is closer to the base station.

According to a third aspect of the present invention, in the wireless communication system according to the first or second aspect, a plurality of relay stations installed between two adjacent concentric circles in the plurality of concentric circles centering on the base station. Is set at least based on the same predetermined time and different unique times assigned to each of the plurality of relay wireless stations.

[0014] According to a fourth aspect of the present invention, in the wireless communication system according to any one of the first to third aspects, the standby time includes a distance between the relay station and the base station;
The setting is made based at least on an arbitrary transmitting station or an arbitrary relay station and a direction in which the relay station is located.

According to a fifth aspect of the present invention, in the wireless communication system according to any one of the first to fourth aspects, the relay station determines at least a part of the deciding factor for determining the waiting time by the transmitting station or another transmitting station. The setting is based on transmission data transmitted from the relay station.

According to a sixth aspect of the present invention, in the wireless communication system of the first aspect, the relay station performs the relay communication when a predetermined communication quality is obtained. I do. In this case, the communication quality includes S
/ N ratio, bit error rate, received signal distortion rate, and the like.

According to a seventh aspect of the present invention, there is provided a wireless communication system according to any one of the first to sixth aspects, wherein the base station transmits one or more relay stations to another relay station or a transmitting station. The transmission data is configured to be capable of relay communication.

In the wireless communication system according to the present invention, when transmitting transmission data from the base station to another relay station or a transmitting station, the standby time may be shorter than that of the base station. , The relay station is set at a shorter time for a farther relay station.

According to a ninth aspect of the present invention, in the wireless communication system according to any one of the first to eighth aspects, the transmitting station and the relay station transmit communication path data for specifying a communication path of the relay communication. It is characterized by being inserted into transmission data and transmitted.

According to a tenth aspect of the present invention, in the wireless communication system according to the ninth aspect, the base station transmits the answer back data after receiving the transmission data to an arbitrary transmitting station or an arbitrary transmitting station from which the transmission data is transmitted. When transmitting to one or more relay stations, one or more relay stations transmit transmission data capable of relay communication according to the communication path specified by the communication path data.

According to an eleventh aspect of the present invention, in the wireless communication system according to any one of the first to tenth aspects, the base station transmits predetermined information based on transmission data transmitted from the transmitting station to a public communication line. It is characterized by being configured to be able to communicate with another base station or management station via a network.

A wireless communication system according to a twelfth aspect of the present invention is the wireless communication system according to any one of the first to eleventh aspects, wherein the transmitting station is an abnormality notification device in a vacuum-type sewage collection system.

According to a thirteenth aspect of the present invention, in the wireless communication system according to the twelfth aspect, the transmitting antenna of the transmitting station is arranged along an intake pipe arranged in parallel with a sewage tank in a vacuum type sewage collection system. It is characterized by being provided.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which a wireless communication system according to the present invention is applied to a vacuum-type sewage collection system will be described below with reference to the accompanying drawings.

First, the configuration of the vacuum-type wastewater collection system S1 will be described with reference to FIG.

As shown in FIG. 1, the vacuum type sewage collection system S1 is a system for sucking and collecting sewage discharged from a sewage tank 10 installed at home or the like to a vacuum station provided with a vacuum device. A plurality of transmitting stations ST installed in each home, etc., a plurality of relay stations SR installed in each home and also functioning as the transmitting station ST, and one base station SB functioning as a vacuum station. It is configured. The relay station SR may be separately and independently installed on the roof of a building different from the home and may have only the relay function. Hereinafter, an example in which the transmission station ST is shared will be described. Further, the base station SB may be installed at a predetermined location different from the vacuum station, but an example in which the base station SB is installed in the vacuum station will be described below.

In this vacuum type sewage collection system S1, each transmitting station ST and each relay station SR are provided with a sewage tank 10,
A transmitter / receiver 11 installed in the sewage basin 10, a sewer pipe 12 connected to the sewage basin 10, a down pipe 13 for flowing sewage down the sewage basin 10, and a suction pipe connected to the sewage pipe 12 A suction pipe 14, a sewage amount detection pipe 15 for detecting the amount of sewage by the pressure difference between the inside and outside of the sewage tank 10, and a vacuum valve for opening or closing a valve to open or close the sewage pipe 12 and the suction pipe 14. 16, a vacuum valve opening / closing controller 17 for controlling opening / closing of the vacuum valve 16,
The vacuum valve opening / closing controller 17 has an intake pipe 18 for taking in outside air, and an antenna 19 disposed along the intake pipe 18 so as to partially expose the intake pipe 18 for improving radiation efficiency. ing. When the intake pipe 18 is formed of resin, the antenna 19 may be disposed inside the intake pipe 18 so as not to be exposed to the outside.

In this case, as shown in FIG. 4, the transceiver 11 transmits the transmission signal STR to the transmission section 31 and transmits the transmission signal STR transmitted from another transmission station ST for relay communication to the reception signal SRE. Receiving section 32 for receiving as
And a control unit 33 for controlling the operation of the receiving unit 32, a ROM 34 for storing an operation program of the control unit 33, data for determining a standby time TD described later, and various data for generating the transmission signal STR. And
When the transmitting station ST and the relay station SR are distinguished in advance and the transmitting station ST has only the transmitting function, the transmitting station ST does not need the receiving unit 32.

In the transceiver 11, the ROM 34 stores
A program for performing the relay communication when a predetermined standby time elapses after receiving the transmission signal STR is stored, and the standby time TD is set to be different from each other by each relay station SR. It is specified in advance. For this reason, for example, the standby time of the time TD1 is stored in the ROM 34 of the relay station SR1, and the ROM 3 of the relay station SR2 is stored.
4 stores a standby time of a time TD2 longer than the time TD1, as shown in FIGS. 3A and 3B, the relay station SR1 and the relay station SR2 simultaneously receive the reception signal. When receiving the SRE, the relay station SR1 starts relay communication of the transmission signal STR when the time TD1 has elapsed.
At the same time, the relay station SR2, when the time TD2 has elapsed,
An attempt is made to start relay communication of the transmission signal STR. In this case, the receiving section 32 of the relay station SR constantly monitors the presence or absence of the transmission signal STR by another relay station SR or the transmission station ST by the carrier sense during the standby time TD, and the reception electric field of the reception signal SRE is When the intensity exceeds a predetermined level, the control section 33 outputs a carrier sense signal SC to the control section 33. At this time, the control unit 33
While the carrier sense signal SC is being output from, the transmission of the transmission unit 31 is prohibited.

Therefore, in the above example, the relay station SR1
Starts the relay communication after the elapse of the standby time TD1. On the other hand, the relay station SR2 attempts to start relay communication after the elapse of the standby time TD2, but within the standby time TD2,
Receives the transmission signal STR transmitted by the carrier sense, the relay communication is prohibited by the carrier sense. Therefore,
Of the relay stations SR whose received signal strength of the received signal SRE exceeds a predetermined level, only one relay station SR having a shorter standby time TD performs relay communication preferentially.

When the answer back data, which will be described later, is transmitted from the base station SB, the control unit 33 of the transceiver 11 relays the relay specified by the communication path data inserted in the answer back signal. As relay communication is performed via the station SR to the transmitting station ST,
The communication path data is inserted into the transmission data and transmitted.

On the other hand, as shown in FIGS. 5 and 6, a vacuum pump 21, a water collecting tank 22, a transceiver 2
3, control unit 24, display unit 25, transmitting / receiving antenna 26
And a modem 27 are provided. In this case, the transceiver 23 converts the transmission signal STR transmitted by each transmitting station ST or the relay station SR into the reception signal SRE, as shown in FIG.
And a transmission unit 42 for transmitting an answerback signal as a transmission signal STR when receiving the reception signal SRE. The reception unit 41 and the transmission unit 42 are controlled by the control unit 24. You. The control unit 24 includes, for example, a control circuit 43 that is configured by a CPU and controls the operation of the transceiver 23, and a ROM 44 that stores an operation program of the control circuit 43 and various data when creating transmission data. I have.

In the vacuum-type wastewater collecting system S1, the inside of the water collecting tank 22 is depressurized by the operation of the vacuum pump 21, and the inside of the sewer pipe 12 connected to the water collecting tank 22 is depressurized. On the other hand, at each sewage tank
When the sewage flows down into the sewage trough 10 through the downflow pipe 13, the internal pressure of the sewage trough 10 increases, and the increase in the internal pressure is detected by the vacuum valve opening / closing controller 17. At this time, the vacuum valve opening / closing controller 17 controls the vacuum valve 16 to open for a predetermined period of time, so that the suction pipe 14 and the sewer pipe 12
The sewage in the sewage tank 10 is sucked into the water collecting tank 22 via the suction pipe 14 and the drain pipe 12. Next, by operating a pump (not shown) installed in the base station SB, the sewage collected in the water collection tank 22 is treated after being sent to the sewage treatment plant.

When an abnormality occurs in the vacuum valve 16, an abnormality signal SA is output from the vacuum valve 16 to the transceiver 11, and at this time, the control unit 33 sends the abnormality data DA to the transmission unit 31. The transmission unit 31 outputs the transmission signal STR modulated by the transmission data DT via the antenna 19 by outputting the transmission data DT into which the transmission data DT is inserted.
In this case, the transmission radio wave is transmitted to the base station SB via the relay station SR.
Is relayed. As a result, the control unit 24 of the base station SB
Identifies the sewage tank 10 in an abnormal state based on the abnormal data DA included in the reception data DR output from the transceiver 23, and displays on the display unit 25 that the sewage tank 10 is abnormal. . The base station SB may be an unmanned station. In this case, the control circuit 43 sends the abnormal data D via the modem 27 and the public communication network N.
A is communicated to the manned management station SM. As a result, the abnormality of the sewage tank 10 is detected as soon as possible.
Abnormal decompression state in 2 can be avoided. Further, the control circuit 43 includes the public communication network N and the modem 2
Various controls can be performed on the basis of control data communicated from the manned management station SM via the control unit 7.

Next, a relay communication system in the vacuum-type wastewater collection system S1 will be described. In the following, for ease of understanding, a description will be given assuming that the transmitting station ST and the relay station SR are distinguished in advance. Therefore,
As shown in FIG. 1, the vacuum type wastewater collection system S1 includes a number of transmission stations ST1 to ST1 around a base station SB.
STN is installed, and each transmitting station ST and base station SB
Between the relay stations SR1 to SRM.

First, the waiting time T for each relay station SR
A method for providing D will be described. Conceptually, when relaying communication from the transmitting station ST or the relay station SR to the base station SB, the standby time TD is set to be shorter as the relay station SR is closer to the base station SB. Is given to
In this case, it is not necessary to set strictly for all the relay stations SR so that the relay station SR which is closer to the base station SB has a shorter time. That is, it is important that the standby times TD given to the plurality of relay stations SR existing within the range where the transmission radio waves transmitted from the arbitrary transmitting station ST or the arbitrary relay station SR reach each other are different from each other. Further, in the plurality of relay stations SR, it is not always necessary to strictly set the relay station SR closer to the base station SB so that the shorter the distance, the shorter the distance between the base station SB and the base station SB. The standby time TD of the farther relay station SR is equal to the base station S
The standby time TD of the relay station SR closer to B may be shorter than the standby time TD. When the base station SB performs relay communication with the transmission source ST via the relay station SR, such as when transmitting answerback data, the base station S
The relay station SR is given such that the shorter the relay station SR, the shorter the time.

By providing the standby time TD in this manner, a transmission signal STR transmitted from an arbitrary transmission station ST or a transmission station ST can be transmitted, for example, by a plurality of reception signals having a reception field strength exceeding a predetermined reception field strength. Of the relay stations SR, only the relay station SR having the shortest standby time TD relays the transmission data DT included in the transmission signal STR. In this case, when a failure occurs in the relay station SR whose standby time TD is the shortest among the plurality of relay stations SR, the relay station SR whose standby time TD is the next shortest is replaced by the failed relay station SR. Relay communication is performed in place of the station SR. Therefore, as a result of having a backup function of the failed relay station SR, even if a failure occurs in one relay station SR, the influence on the entire vacuum-type wastewater collection system S1 becomes extremely small, Thereby, the reliability of the system can be improved.

Also, unlike the conventional wireless communication system S11 in which a communication path is set in advance, an automatic and dynamic communication is performed so that the relay station SR located closer to the base station SB performs relay communication. Is set to the relay station SR. In addition, since the communication path is automatically determined according to the propagation state of the transmission radio wave, as compared with the conventional wireless communication system S11, the larger the number of relays, the more the relay communication from the transmitting station ST to the base station SB. The required communication time can be shortened. At the same time, since the number of relays is reduced, for example, when the relay station SR is driven by a battery, low power consumption can be achieved, whereby the relay station SR operates continuously for a long period of time. Can be done. Further, since it is not necessary to perform desk calculations such as reception electric field strength calculations and field surveys to determine a communication path, it is possible to reduce the system cost and to construct a communication system in a short time. .

Next, a specific method of giving the standby time TD will be described. First, an example of determination of the waiting time TD is shown in the following equation. TD = 1.0 × R + 0.25 × D + 0.01 × A (second) ... Expression

In the equation, "R" means a parameter proportional to the distance, and a value obtained by multiplying the coefficient (1.0) by the value of the parameter R corresponds to a predetermined time in the present invention. This “R” is given a value of 0 to all the relay stations SR installed inside the circle of R = 0 shown in FIG. 1, and similarly, R = 1 adjacent to the circle of R = 0 The value 1 is given to all the relay stations SR installed between the concentric circles. Similarly, a value 2 is given to all the relay stations SR installed between two concentric circles of R = 1 and R = 2, and a value of 2 is provided between two concentric circles of R = 2 and R = 3. Is assigned a value of 3 to all the relay stations SR installed in. Thereby, the shorter the relay station SR is, the shorter the standby time TD is set to the base station SB. In this case, the value of the parameter R is stored in advance in the ROM 34 in the transceiver 11 in each relay station SR.

Further, "D" in the expression is the relay station S on the reception side with respect to the transmission station ST or the relay station SR of the transmission destination.
The parameter indicates the direction of R. Specifically, in the figure, for example, a case where the transmitting station ST1 has transmitted will be described. First, each relay station SR is plotted on the XY axis centering on the base station SB (0, 0), and
If the Y-axis is divided into the first quadrant to the fourth quadrant, D = 0 is assigned to each relay station SR in the third quadrant that is the same quadrant. In addition, each relay station SR in the quadrant in the clockwise direction of the quadrant (in this example, the fourth quadrant)
, D = 1 is assigned, and D = 2 is assigned to each relay station SR in the quadrant in the counterclockwise direction of the quadrant (in this example, the second quadrant). D = 3 is assigned to each relay station SR in the opposing quadrant (first quadrant in this example). As a result, among the relay stations SR to which the parameter R having the same value is given, the shortest standby time is set for the transmission station ST or the relay station SR installed in the same quadrant as the relay station SR. A time TD is provided. Also, the transmission destination station ST or the relay station SR
, The next short standby time TD is given to the relay station SR installed in the clockwise direction, and the next short standby time TD is applied to the relay station SR installed in the counterclockwise direction. And the longest standby time TD is given to the relay station SR installed in the opposing quadrant.

As a result, the relay route is set to the transmission station S of the transmission destination.
T or a relay station SR installed in the same quadrant as the relay station SR in order to perform relay communication in order, so that the number of relays is minimized, and the communication path is determined to be the shortest path in terms of time and distance. Is done. Also, a relay station SR exceeding a predetermined reception electric field strength is provided to the relay station SR in the same quadrant.
When there is no communication route, the communication route is preferentially determined so as to be clockwise. As a result, it is possible to prevent relay communication by the relay station SR that is extremely deviated from the communication route, such as the relay station SR installed in the opposing quadrant. In addition, redundant relay communication via another communication path can be prevented.

On the other hand, “A” in the equation means a unique parameter given to a plurality of relay stations SR installed between two concentric circles adjacent to each other, and the unique parameter is an integer different from each other. Is determined. Also,
The value obtained by multiplying the coefficient (0.01) by the value of the parameter A corresponds to the characteristic time in the present invention. Note that the coefficients for the parameters R, D, and A are merely examples, and the coefficient for the parameter D is set to a value of 0.25 because:
Relay station SR installed between two concentric circles adjacent to each other
Is assumed to be less than or equal to 24 stations, and when the number of relay stations SR installed between the concentric circles exceeds 24 stations, a new coefficient may be separately set, and the parameter A
May be set to a positive real number within a range not exceeding 24. The value of parameter A is stored in advance in ROM 34 in transceiver 11 in each relay station SR.

When the base station SB performs relay communication with the transmitting station ST via the relay station SR, the standby time TD is determined based on, for example, the above equation. Specifically, the parameter D in the expression is set to the direction of the relay station SR on the receiving side with respect to the base station SB as the transmission destination, and the reciprocal of the waiting time TD obtained by the expression is multiplied by a predetermined coefficient to obtain the actual value. The waiting time TD can be easily determined. Of course, the standby time TD determined by this method is shorter for the relay station SR farther away from the base station SB.

Next, a communication method in the vacuum-type wastewater collection system S1 will be described.

For example, in the transmitting station ST1, the vacuum valve 1
When an abnormality occurs in 6, an abnormality signal SA is output from the vacuum valve 16 to the transceiver 11. At this time, in the transceiver 11, the control unit 33, which has received the abnormal signal SA, outputs the transmission data DT to the transmission unit 31 and controls the transmission state. In this case, the transmission data DT is represented by FIG.
As shown in (a), preamble data, bit synchronization data, frame synchronization data, call name data which is the station number of the base station SB, and the above-described first to fourth quadrants for the base station SB. Direction data indicating which one belongs to, distance data of the own station corresponding to the value of “R” described above,
An error data DA indicating the content of the error, a data body including the ID data of the own station, a path length data indicating the number of relays,
It is composed of n pieces of route data for specifying the communication route into which the station numbers of the transmitting station ST and the relay station SR are inserted, and an error correction code. In this case, when the transmitting station ST1 performs transmission, a value 1 is inserted as the path length data and a value 1 is inserted as the path 1 data in the transmission data DT as shown in FIG. Next, the transmission section 31 outputs a transmission signal STR to the antenna 19 based on the transmission data DT, so that a transmission radio wave is emitted from the antenna 19.

When the transmission signal STR is transmitted by the transmission station ST1, the transmission signal STR is transmitted by a plurality of relay stations SR.
TR is received. At this time, the plurality of relay stations SR that have received the reception signal SRE with the reception electric field strength exceeding the predetermined reception electric field strength first set the standby time TD of the own station. That is, the control unit 33 of the relay station SR located in the quadrant indicated by the direction data inserted in the transmission data DT substitutes the value 0 as the parameter D in the above equation and is given to the own station in advance. The standby time TD is calculated by substituting the values of the parameters R and A into the equation. The control unit 33 of the relay station SR installed in the clockwise quadrant with respect to the transmitting station ST1 similarly sets the parameter D
The standby time TD is calculated by substituting the value 1 and the values of the parameters R and A. Similarly, the control unit 33 of the relay station SR installed in the quadrant in the counterclockwise direction with respect to the transmitting station ST1 substitutes the value 2 as the parameter D and the values of the parameters R and A to set the standby time TD And the control unit 33 of the relay station SR installed in the quadrant opposite to the transmitting station ST1 calculates the standby time TD by substituting the value 3 as the parameter D and the values of the parameters R and A. I do. In this way, each relay station SR can reliably and easily collect information on the direction of the own station with respect to the transmitting station ST (or the relay station SR) on the transmitting side, and based on this information, determine the standby time TD. It can be easily set.

Next, the control unit 33 of each relay station SR monitors the carrier sense signal SC output from the receiving unit 32. Within the standby time TD, the carrier sense signal SC
Station S that has determined that is not output from the receiving unit 32
The R control unit 33 transmits the transmission data DT created on the basis of the reception data DR output from the reception unit 32 to the transmission unit 31.
And the transmitting unit 31 is controlled to be in a transmitting state. In this example, it is assumed that the relay station SR1 transmits data. In this case, as shown in FIG. 2B, the transmission data DT has a value 2 for the path length data, a value 1 for the path 1 data, and a path 2 for the path 1 data. The value 1 which is the own station number is inserted into the data. Similarly,
When the transmission signal STR is transmitted from the relay station SR1, the relay station SR1 is used as the second relay station in the same manner as described above.
4, the relay station SR4 determines that the value of the route length data is 3, the value of the route 1 data is 1, and the value of the route 2 is set as shown in FIG.
The transmission data DT in which the value 1 is inserted into the data and the value 4 which is the own station number is inserted into the route 3 data is transmitted. It should be noted that the control unit 33 of the relay station SR uses the I inserted in the data body.
When the D data receives the same transmission data DT repeatedly, transmission of the transmission data DT is prohibited to prevent retransmission.

Next, the transmission signal ST transmitted by the relay station SR4 is received by the transceiver 23 of the base station SB. At this time, the control circuit 43 of the control unit 24 in the base station SB receives the reception data D output from the reception unit 41.
The contents of the abnormality are specified based on the abnormal data DA inserted in the data body of R, and the station number of the transmitting station ST is specified based on the ID data. Next, the control circuit 4
3 causes the display unit 25 to display the content of the abnormality and the station number.

Thereafter, the control circuit 43 indicates to the transmitting section 42 the data itself, the ACK data indicating that the data has been received, and the communication path specified by the data 1 to n in the transmission data DT. It outputs the communication path data as answerback data DAB and controls the transmission state. Accordingly, each relay station SR that has received the answerback data DAB transmitted by the transmitting unit 42 prohibits the relay communication of the transmission data DT in which the same data body is inserted. As a result, retransmission of the transmission data DT of the same content by the relay station SR can be prevented, and even if the transmission signal STR arrives by bypassing another communication path, the transmission data DT of the transmission data DT is not transmitted. Retransmission can be prevented.

Further, the control unit 33 of the relay station SR in which the own station number is inserted in the communication path data in the answer back data DAB is used by the relay station SR or the transmission destination of the next transmission destination specified by the communication path data. The transmission data in which the answerback data DAB is inserted is relayed to the station ST. As a result, the answer back data DAB is relayed on the communication path opposite to the communication path when the relay communication is performed from the transmitting station ST to the base station SB. In this case, since the relay communication has been normally performed from the transmission station ST to the base station SB, the answerback data DAB is reliably relayed to the transmission station ST of the transmission source. Thereby, the reliability of relay communication can be improved.

The present invention is not limited to the configuration shown in the embodiment of the present invention. For example, in the embodiment of the present invention, an example in which the transmitting station ST is used as the relay station SR has been described. For example, when the transmitting station ST is driven by a battery, only the transmitting function is provided to the transmitting station ST. , The transmitting station ST can be operated continuously for a long period of time. Further, the wireless communication system of the present invention is not limited to the data contents shown in the embodiment of the present invention, and it is needless to say that the wireless communication system can be appropriately added and changed. Further, the configurations of the transceiver 11 and the transceiver 23 are not limited, and can be appropriately changed. As for the frequency to be used, not only a single frequency but also a multi-channel access method or the like can be adopted.

Further, the method of determining the standby time in the present invention is not limited to the method described in the embodiment of the present invention.
It can be changed as appropriate. For example, in the embodiment of the present invention, a parameter R having the same value is given to a plurality of relay stations SR installed between two adjacent concentric circles.
The present invention is not limited to this, and different eigenvalues may be assigned to all the relay stations SR. Also, the parameter D need not necessarily be provided.

[0054]

As described above, according to the radio communication system according to the first aspect, each of the relay stations capable of directly receiving transmission data transmitted from an arbitrary transmitting station or an arbitrary relay station is provided to each other. By giving different waiting times,
By preventing redundant relay communication and essentially providing a backup function of a failed relay station, even if a failure occurs in one relay station, the effect on the entire communication system is extremely reduced. Therefore, the reliability of the system can be improved. In addition, desk calculation such as reception electric field strength calculation and field survey for determining a communication path are not required, so that the system cost can be reduced accordingly.

According to the wireless communication system of the present invention, by setting the relay station closer to the base station to a shorter time, the communication path becomes shorter according to the propagation condition of the transmission radio wave. Since the communication route is automatically determined, it is possible to determine the route with the least number of relays and the shortest time and distance in the communication route. At the same time, lower power consumption at the relay station can be achieved by reducing the number of relays.

According to the wireless communication system of the third aspect, a plurality of relay stations installed between two concentric circles adjacent to each other in a plurality of concentric circles centered on the base station have the same predetermined time. By setting the standby time determined based on the and the specific time, different standby times can be simply and reliably provided to the plurality of relay stations.

According to the wireless communication system of the present invention, the standby time is based at least on the distance of the relay station to the base station and the direction in which the relay station is located with respect to any transmitting station or any relay station. By setting, the positional relationship between the transmitting station or the relay station on the transmitting side and the relay station on the receiving side can be taken into consideration, so that relay communication by a relay station extremely deviating from the communication path can be prevented. As a result, redundant relay communication via another communication path can be prevented.

Further, according to the wireless communication system of the fifth aspect, at least a part of the deciding factor for determining the standby time is set based on the transmission data transmitted from the transmitting station or another relay station. The relay station can, for example, reliably and easily collect information about its own direction with respect to the transmitting station or the relay station on the transmitting side, and thereby set a standby time based on the information about this direction. be able to.

Further, according to the radio communication system of the sixth aspect, the relay station performs the relay communication when the predetermined communication quality is obtained, so that high reliability of data can be secured. In addition, by appropriately changing the level of the reception electric field strength, the relay distance between the relay station or the transmission station and the relay station that receives the transmission radio wave transmitted from these stations and relays the communication can be arbitrarily determined. Can be.

According to the radio communication system of the present invention, the transmission data can be relayed from the base station to another relay station or the transmission station via one or more relay stations. As a result of transmitting an answer back signal or the like from the base station to the transmitting station or the relay station, the reliability of the relay communication can be improved.

According to the wireless communication system of the present invention, when transmission data is transmitted from the base station to another relay station or transmission station, the standby time is longer than the base station. By setting the station as short as possible, relay communication can be performed reliably and quickly from the base station to the transmitting station, whereby the reliability of the system can be improved.

Further, according to the radio communication system of the ninth aspect, the transmitting station and the relay station insert the communication path data into the transmission data and transmit the data, so that the transmission is performed from the transmission station to the base station. The communication path of the relay communication can be easily specified.

According to the radio communication system of the tenth aspect, the base station transmits transmission data that can be relayed by one or more relay stations in accordance with the communication path specified by the communication path data. The answerback data after receiving the transmission data can be reliably relayed to the transmission station or the relay station of the transmission source.

According to the radio communication system of the present invention, the base station transmits predetermined information based on the transmission data transmitted from the transmission station to another base station or the management station via the public communication network. By communicating, relay communication using a public communication network to a manned base station or management station can also be performed.

According to the wireless communication system of the twelfth aspect, it is possible to provide a vacuum-type wastewater collection system with higher reliability.

According to the radio communication system of the thirteenth aspect, by arranging the transmitting antenna of the transmitting station along the intake pipe, the radiation efficiency of the antenna can be reduced without providing a building for installing the antenna. Can be improved.

[Brief description of the drawings]

FIG. 1 is a layout diagram of a base station, a transmitting station, and a relay station in a vacuum-type sewage collection system S1 according to an embodiment of the present invention.

FIGS. 2A to 2C are data structure diagrams showing the data contents of transmission data DT.

FIG. 3 is a diagram illustrating a principle of determining a communication path,
(A) is a timing chart showing the transmission timing of the relay station SR1, and (b) is a timing chart showing the transmission timing of the relay station SR2.

FIG. 4 is a block diagram of the transceiver 11 in the transmitting station ST and the relay station SR.

FIG. 5 shows a transceiver 23 and a control unit 2 in the base station SB.
FIG. 4 is a block diagram of a display unit 25, a modem 27, and the like.

FIG. 6 is a configuration diagram of a vacuum-type sewage collection system S1 according to an embodiment of the present invention.

FIG. 7 is a layout diagram of a base station, a transmitting station, and a relay station in a conventional wireless communication system S11.

[Explanation of symbols]

 11 Transceiver 19 Antenna 23 Transceiver S1 Vacuum-type wastewater collection system SB Base station SR Relay station ST Transmitting station

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2D063 AA07 BA16 BA37 5K072 AA24 BB17 BB25 BB27 CC02 DD16 DD17 EE04 EE13 EE21 GG11 GG12 GG14 HH01

Claims (13)

[Claims] A plurality of transmitting stations and a plurality of relay stations;
A wireless communication system comprising at least one base station and configured to be able to relay and transmit transmission data from any of the transmitting stations to the base station via one or more of the relay stations; Or each of the relay stations capable of directly receiving the transmission data transmitted from any of the relay stations is configured to be capable of relay communication when a predetermined standby time has elapsed after receiving the transmission data, and A wireless communication system, wherein a different waiting time is provided. 2. The wireless communication system according to claim 1, wherein the standby time is set shorter for a relay station that is closer to the base station. 3. The standby time of a plurality of relay stations installed between two concentric circles adjacent to each other in a plurality of concentric circles centered on the base station is the same predetermined time and the plurality of relay radios. The wireless communication system according to claim 1, wherein the wireless communication system is set based at least on different unique times assigned to each of the stations. 4. The standby time is set based on at least a distance of the relay station to the base station and a direction in which the relay station is located with respect to the arbitrary transmitting station or the arbitrary relay station. Claims 1 to 3 characterized by the above-mentioned.
The wireless communication system according to any one of the above. 5. The relay station according to claim 1, wherein at least a part of the determining factor for determining the waiting time is set based on the transmission data transmitted from the transmitting station or another relay station. Item 5. The wireless communication system according to any one of Items 1 to 4. 6. The relay station according to claim 1, wherein the relay station performs relay communication when a predetermined communication quality is obtained.
The wireless communication system according to any one of the above. 7. The relay apparatus according to claim 1, wherein transmission data can be relayed from said base station to another relay station or said transmission station via one or more relay stations. 7. The wireless communication system according to any one of 6. 8. When transmitting the transmission data from the base station to the other relay station or the transmitting station, the standby time is shorter for the relay station that is farther from the base station. The wireless communication system according to claim 7, wherein 9. The transmission station according to claim 1, wherein the transmission station and the relay station insert communication path data for specifying a communication path of the relay communication into the transmission data and transmit the data. The wireless communication system according to any one of the above. 10. The base station, when transmitting answerback data after receiving the transmission data to the arbitrary transmitting station or the arbitrary relay station that is the transmission source of the transmission data, transmits the communication path data. 10. The wireless communication system according to claim 9, wherein the one or more relay stations transmit transmission data capable of performing relay communication according to the communication path specified by: 11. The base station is configured to be able to communicate predetermined information based on transmission data transmitted from the transmission station to another base station or a management station via a public communication network. The wireless communication system according to any one of claims 1 to 10, wherein 12. The wireless communication system according to claim 1, wherein the transmission station is an abnormality notification device in a vacuum-type sewage collection system. 13. The wireless communication system according to claim 12, wherein the transmitting antenna of the transmitting station is disposed along an intake pipe arranged in parallel with a sewage tank in the vacuum type sewage collection system. Communications system.