JPH10224316A - Time division multiplex access communication method, and automatic tracing monitor method and device for a plurality of mobile bodies using this method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain automatic tracing monitor for mobile bodies by transmitting data such as position, travelling direction and speed of mobile stations to a base station through the use of generation, synchronization and assignment of time slots of time division multiplex access(TDMA) communication system without the use of a highly precise reference clock. SOLUTION: A base station 1 sends a master signal for a prescribed period of one data cycle, each reception station 7 of each user receives respectively the master signal and measures the period of one data cycle of the received master signal. Each reception station divides one data cycle into number of time slots set by each reception station based on the master signal so as to generate time slots for transmission of data of its own station respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a time division multiplexing access communication method.
communication system, hereinafter referred to as a TDMA communication method), to create a time slot for transmitting data,
It relates to the synchronization and allocation method. further,
By transmitting mobile station data such as the position, traveling direction, and speed of mobile units and obstacles such as aircraft, vehicles, and ships, and fixed stations (hereinafter, all referred to as mobile stations) using the TDMA communication method, to the base station. And a method and an apparatus for automatically and subordinately monitoring these moving objects.

[0002]

2. Description of the Related Art The TDMA communication method is a method in which a communication channel of one carrier frequency is divided into a number of time slots, and a user is assigned to each of the time slots to perform multiplexing. For example, as shown in FIG. 3, one data cycle is divided into eight time slots, a base station transmits a master signal Ma at a constant period of one data cycle, and mobile stations A, B,. , The time slots T _S3 , T _S4.
The mobile station transmits its own mobile data S1 and S2.

[0003] On the other hand, in order to ensure the safe and smooth operation of aircraft and vehicles navigating in airports, ships navigating in the sea or in harbors, vehicles traveling on roads, etc., these mobile units are generally used as base stations. Monitoring and control methods have been proposed.

[0004] As an example, as shown in FIG. 5, an automatic dependent monitoring (ADS: Automatic Dependent Surveillance) adopted for monitoring of a moving body and the like proposed by the present inventors has been proposed.
There is a way. In this method, the position of the mobile unit 20 on which the mobile station is mounted is determined using the GPS 30 and this mobile unit data is transmitted to the base station 21 via an arbitrary communication medium. Base station 21
And temporarily transmits the data to a higher-order upper base station 22 via a high-speed communication network.
The data is collectively stored in the data table 24 via the organizer 23, and the mobile data of the mobile 20 is stored in the host computer.
The data is read out by the data 25 and displayed on the display device 26 to monitor each moving body 20 as a whole.

[0005] Further, the base station 21 collects courses, distances, positional relationships, and the like of each mobile unit 20 and monitors each mobile unit 20 while displaying the collected data. The data is transmitted to the mobile unit 20 side, and the mobile unit 20 also receives its own mobile unit data and the mobile unit data of another mobile unit 20 to use it for collision prevention and the like.

Trains and aircraft such as Shinkansen trains transmit their own mobile data to the central control room of the base station by various communication means independent of each other, or are monitored by other position detecting devices. ing. As a communication means, for example, in the case of a Shinkansen, a sensor for detecting the passage of a train is arranged at a predetermined interval along the track, and when this sensor detects the passage of the train,
This detection signal is transmitted to the central control room. In the main control room, the data of all the trains collected in this way are displayed, where they are monitored and controlled.

[0007] In the case of an aircraft, an ARSR (airway surveillance radar), ASR (airport surveillance radar), SSR (secondary surveillance radar), and ASDE (airport surveillance radar) are used. The detected features are displayed on the display device of the control tower, and are monitored and monitored.
Controlled. In addition, companies that provide trucking services such as courier services have their own operation management systems. These systems use a driver's telephone or radio from each predetermined location to determine their location. The operation status of all vehicles is managed in the central command room based on the results.

As described above, the master signal from the base station is received, and each mobile unit transmits its own mobile unit data. The TDMA communication method is used for the data link of such a system. Although considered to be suitable, this TDMA communication method still has various problems for use in the above-described automatic slave monitoring system.

[0009]

As described above, the TDMA
In the system using the communication method, each mobile station divides the same carrier frequency and transmits its own mobile data to the base station at the time allocated to each time slot.
In order to divide one data cycle into a plurality of time slots, the entire system must operate at one reference time. Therefore, it is necessary to use a high-precision clock such as a GPS time or an atomic clock as a reference clock. Therefore, each mobile station must have a high-precision clock.

[0010] However, when the GPS time is used as a reference, a GPS receiver is required, which causes a problem that the cost of the mobile station increases accordingly. On the other hand, when an atomic clock is used, its price is expensive. Therefore, providing such an expensive device or clock for all the mobile stations for the reference time has a problem that the cost of the mobile station is increased accordingly.

Even if the mobile station is provided with such a precise and expensive clock, if any mobile station whose reference time is shifted for some reason enters the system, the mobile station is not provided with the clock. Transmits its own mobile data at a time other than its own time slot. Therefore, the time slot of the own station and the time slot of the other station overlap, and there is a problem that the entire system cannot be established.

Furthermore, in the TDMA communication method, a long guard time is set before and after transmitted data in order to compensate for a signal propagation time delay due to the distance between the base station and the mobile station. Therefore, particularly in a system having a wide communication coverage area, the number of time slots that can be obtained in one data cycle is reduced by the amount corresponding to the guard time, and the number of mobile stations that can join one system is reduced accordingly. .

In the TDMA communication method, each mobile station arbitrarily joins and leaves the system. If the number of available time slots in the system is small, a situation occurs in which a plurality of mobile stations select the same time slot at the same time.

In many cases, when a mobile station joins the system, the selection order of which time slot to select in one data cycle is specified by a simple method such as the order of the youngest slot. When time slots collide with a plurality of mobile stations as described above, the mobile stations that have selected the same time slot cannot recognize that they are in a collision state with each other because they are all in a transmission state.

[0015] The collision of the time slots of a plurality of mobile stations is determined by the base station that has received the signal from the mobile station. As a result, the base station transmits the timeslot numbers that collide with each other on the master signal. Each mobile station receiving this master signal changes the time slot and re-joins each other. However, since two or three mobile stations perform the re-joining operation at the same time, there is a problem that time slots collide again. there were.

[0016]

According to a first aspect of the present invention, there is provided a time division multiple access communication method in which a communication channel of one carrier frequency is divided into a number of time slots, and a user is assigned to each time slot and multiplexed. , A master signal is transmitted from the base station at a fixed cycle of one data cycle, and each receiving station of each user receives the master signal and measures the cycle of one data cycle of the received master signal. One data cycle is divided into the number of time slots set in the receiving station on the basis of the master signal, and time slots for transmitting data of the own station are created.

A second invention is a time division multiple access communication method in which a communication channel of one carrier frequency is divided into a number of time slots, and a user is assigned to each time slot for multiplexing. The master signal is transmitted at a fixed cycle of the data cycle, and each receiving station of each user receives the master signal, measures the cycle of one data cycle of the received master signal, and divides this one data cycle into the master signal. Is divided into the number of time slots set in the receiving station on the basis of the time slot, and a time slot for transmitting data of the own station is created. In each user's receiving station, the position data of the master signal and each receiving station are used. The distance between the base station and the receiving station is obtained from the measured position data of the own station, and from this distance The receiving station obtains the delay time of the master signal received respectively, is obtained so as to synchronize the base station and each of the receiving stations to correct the time slot that is created by this delay time.

A third invention is a time division multiple access communication method in which a communication channel of one carrier frequency is divided into a number of time slots, and a user is assigned to each time slot and multiplexed. The master signal is transmitted at a fixed cycle of the data cycle, and each receiving station of each user receives the master signal, measures the cycle of one data cycle of the received master signal, and divides this one data cycle into the master signal. Each of the receiving stations generates a time slot for transmitting its own mobile data by dividing the time slot into the number of timeslots set in the receiving station based on the time slot. Randomly selected based on the random number table according to Respectively it is obtained so as to transmit the mobile data of its own station.

According to a fourth aspect of the present invention, there is provided a time division multiple access communication system in which a communication channel of one carrier frequency is divided into a number of time slots, and each time slot is assigned to each mobile station mounted on each mobile unit for communication. In the method of transmitting each mobile data to the base station and automatically monitoring a plurality of mobiles by the method, the base station transmits the generated base station data by a master signal at a constant period of one data cycle. The mobile station receives the master signal,
The period of one data cycle of the received master signal is measured, and this one data cycle is divided into the number of time slots set in the mobile station based on the master signal, and the time for transmitting data of the own station is divided. A slot is created, and one of the created time slots is selected to transmit the mobile data of the own station to the base station.

According to a fifth aspect of the present invention, the base station transmits the generated base station data by a master signal at a constant period of one data cycle, the mobile station receives the master signal, and receives the master signal. The period of one data cycle is measured, and this one data cycle is divided into the number of time slots set in the mobile station based on the master signal, and time slots for transmitting data of the own station are created. In the mobile station, the distance between the base station and the mobile station is obtained from the position data of the base station identified from the master signal and the position data of the own station measured by the mobile station, and each mobile station receives the distance from this distance. Calculate the delay time of the master signal, correct the time slot created in the own station by this delay time, and synchronize the base station and mobile station. Those who like to make.

According to a sixth aspect of the present invention, the base station transmits the generated base station data by a master signal at a constant period of one data cycle, and the mobile station receives the master signal, and receives the received master signal. The period of one data cycle is measured, and this one data cycle is divided into the number of time slots set in the mobile station based on the master signal, and time slots for transmitting data of the own station are created. In the mobile station, the distance between the base station and the mobile station is obtained from the position data of the base station identified from the master signal and the position data of the own station measured by the mobile station, and each mobile station receives the distance from this distance. Calculate the delay time of the master signal, correct the time slot created in the own station by this delay time, and synchronize the base station and mobile station. So that each mobile station has a random number generator,
A time slot of each station is randomly selected based on a random number table by a random number generator, and each mobile station transmits its own mobile data in the selected time slot.

According to a seventh aspect of the present invention, there is provided a time division multiple access communication system in which a communication channel of one carrier frequency is divided into a plurality of time slots, and each time slot is assigned to each mobile station mounted on each mobile unit for communication. According to the method, in a device for transmitting data of each mobile unit to a base station and automatically monitoring a plurality of mobile units, the base station includes a communication control device for creating base station data, and a processing unit for processing various signals. A mobile unit comprising: a transmitting unit for transmitting base station data as a master signal in a data cycle repeated at a constant cycle by a communication channel; and a receiving unit for receiving a signal transmitted in a time slot selected in each mobile station. The receiving unit for receiving the master signal and the period of one data cycle of the master signal are measured. Frequency divider that divides the clock into the set number of time slots, a slot counter that counts the number of time slots, a function that sets the number of time slots in one data cycle, and control of the slot counter and frequency divider A communication control device for generating mobile data, and a transmission unit for transmitting the mobile data generated by the communication control device in a selected time slot, using a time division multiple access communication method. Each mobile data is transmitted to a base station to automatically and independently monitor a plurality of mobiles.

According to an eighth aspect of the present invention, the CPU has a function of correcting a synchronization delay of a time slot created by calculating a delay time of a received master signal.

In a ninth aspect, the CPU further comprises a random number generating function for randomly selecting a time slot of the own station based on a random number table.
Further, in a tenth aspect, the communication control device has a random number generation function.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 The first invention relates to creation of a time slot. Hereinafter, an embodiment according to the invention will be described with reference to FIGS.
This will be described in detail with reference to FIG. FIG. 1 is a configuration diagram showing an embodiment of the present invention, and FIG. 2 is a detailed configuration diagram of main parts of FIG.
FIG. 3 is a time chart of a time slot.

In FIG. 1 and FIG. 2, reference numeral 1 denotes a base station, a communication controller 2 for creating base station data, a master signal of the own station, and each mobile station (mobile station A,
Mobile station B ...), a signal processing unit for processing mobile data, base station data, etc., a transmission unit for transmitting base station data 4, a reception unit for receiving signals from mobile stations 5, various types of It comprises a display 6 for displaying data.

Each mobile station A mounted on each mobile 7
As in the case of the base station 1, a receiving unit 8 for receiving a master signal from the base station 1, a signal processing unit 9 for processing base station data and mobile data created by the own station, and a transmission for transmitting mobile station data It comprises a unit 10, a communication control device 11 for creating various data, and a display 12 for displaying various data.

FIG. 2 shows a detailed configuration diagram of each mobile station (hereinafter, referred to as mobile station A). The receiving unit 8 includes a receiver 8a, an amplifier 8b, and a waveform shaper 8c. The receiver 8a receives a master signal from the base station 1. The signal processing unit 9 includes a signal generator (hereinafter, referred to as SG) 9a for generating a timing signal serving as a reference time, a frequency divider that measures one data cycle, and divides this one data cycle into predetermined time slots. 9
b, a slot counter 9c for counting the divided time slots and a CPU 9 for performing various arithmetic processing and control
d.

The SG 9a need not be as precise as a GPS reference clock or an atomic clock. For example, the time interval of one data cycle is 1 μm, such as a crystal oscillator.
It is sufficient if the measurement can be performed with an accuracy of about s, and a normal reference clock is sufficient, and the cost is lower than that of the conventional high-precision reference clock.

The CPU 9d receives the master signal Ma from the base station 1 and reads the master signal Ma.
A function for setting the number of time slots in a data cycle, a function for processing data in the time slots and sending the data to the communication control device 11, and a function for controlling the frequency divider 9b and the slot counter 9c for creating time slots. , And a random number generator function. In addition,
In the CPU 9d, initial setting conditions for dividing one data cycle preset in the system into a desired number of time slots are set. Therefore, the number of time slots can be arbitrarily changed by changing the initial setting conditions.

The communication control device 11 creates mobile station data to be transmitted from the mobile station A to the base station 1, and also instructs the CPU 9d on which time slot to select. The transmission unit 10 includes an amplifier 10b and a transmitter 10a.
It is transmitted in the designated time slot via 9d.

Next, a method of creating a time slot in the mobile station A will be described. As shown in FIG. 1, the base station data generated by the communication control device 2 is subjected to predetermined signal processing by a signal processing unit 3 and then a master signal Ma is transmitted from the base station 1 at a constant period of one data cycle. 4.

The master signal Ma from the base station 1 is received by the receiver 8a of the mobile station A, and is amplified and waveform-shaped by the amplifier 8b and the waveform shaper 8c, respectively.
d and the signal processing unit 9. A timing signal as a reference clock is input from the SG 9a to the frequency divider 9b. Therefore, in the frequency divider 9b, the SG 9a
One data cycle of master signal Ma is measured with reference to the timing signal from.

In the CPU 9d, time data indicating how many times one data cycle is divided for each system is initially set, and in response to a command from the CPU 9d,
One measured data cycle corresponds to the slot counter 9c.
Are divided into time slots T _S1 , T _S2 ... Having predetermined time data by the frequency divider 9b. In this way, the time slot T having the time data set in this system with respect to the master signal Ma is used.
_S1, T _S2 ··· is created. In this example,
One data cycle is divided into eight.

In the communication control unit 11, mobile station data is created. This mobile station data is transmitted from the transmitter 10a of the transmission unit 10 via the amplifier 10b from the time slot designated by the own station via the CPU 9d. Sent. In the case of this embodiment, as shown in FIG. 3, transmission is performed in the time slot T _{S3 for} the mobile station A, and in the time slot T _S4 for the mobile station B.

[0036]

Embodiment 2 The second invention relates to a method of synchronizing a time slot. Hereinafter, an embodiment of the present invention will be described in detail with reference to FIGS. 1, 2, and 4. FIG. FIG. 4 shows the second
It is a time chart figure of the time slot which shows this invention.

As shown in FIG. 4, when the master signal Ma transmitted from the base station 1 is received by each mobile station A (A, B...), The received master signal Ma1, Ma1,
Ma2... Have a time delay due to the propagation distance of the radio wave between the base station 1 and each mobile station A.

As described in the first embodiment, each mobile station A
Generates time slots T _S1 , T _S2, ... Based on the master signal Ma transmitted from the base station 1. For example, in each mobile station (mobile stations A and B), the master signal Ma from the base station 1 is delayed by a delay time like the received master signals Ma1 and Ma2.

Therefore, in the mobile stations A and B, the time slots are created based on the master signals Ma1 and Ma2 delayed by the delay time, so that the created time slots T _S11 and T _S11 are generated as shown in FIG. _S21 , T _S12 , T _S22
Are delayed by the delay time from the master signal Ma of the base station 1, respectively. Therefore, the base station 1 and the mobile stations A and B are not synchronized.

Therefore, in the second invention, each mobile station A corrects the delay time due to the propagation time of radio waves,
It is intended to reduce the delay time to a one-way distance from each mobile station A to the base station 1.

As shown in FIG. 2, first, in the mobile station A, the position data of the mobile station A is obtained by the mobile body position measuring device 13 such as a GPS receiver. On the other hand, the position data of the base station 1 is obtained by the CPU 9d from the received master signal Ma, and the distance between the base station 1 and the mobile station A is obtained from both positions. In this way, the propagation time of the radio wave is calculated from the distance between the base station 1 and the mobile station A. Therefore,
As shown in FIG. 4, the time slots T _S11 , T _S21.
Are corrected to become time slots T _S1 and T _S2 .

The position data of the mobile station A is calculated by the communication control unit 11 from the mobile body position measuring device 13 such as a received GPS signal, and the result is input to the CPU 9d, and the position data of the mobile station A and the base The propagation time may be calculated from the position data from the station 1. Alternatively, the position data of the base station 1 may be input to the communication control device 11. In this way, the propagation time of the radio wave is calculated from the distance between the base station 1 and the mobile station A. Therefore, FIG.
As shown in (1), the time slot created in the mobile station A is corrected by a time corresponding to the propagation time.

Thus, in all mobile stations A and B,
The mobile station data can be transmitted in time slots synchronized with the time slots of the base station 1. At this time, the delay time when transmitting mobile station data from the mobile station A to the base station 1 is set within an allowable range of the guard time of the master signal Ma of the base station 1. Therefore, the guard time can be set to about half the conventional value.

[0044]

Third Embodiment A third invention relates to a method of allocating time slots. Hereinafter, an embodiment of the present invention will be described in detail with reference to FIGS. In this embodiment, the communication control device 11 has a built-in random number generator for arbitrarily selecting a time slot. The CPU 9
If d has a random number generator, the communication control device 1
1 does not necessarily need to have a random number generator. Other devices are the same as those in the first and second embodiments.

With this configuration, the TDMA
In the communication method, one time slot is assigned to each mobile station A, and its own mobile station data must be transmitted during the time slot assigned to the mobile station. Then, each mobile station A arbitrarily joins and leaves the system. In this case, a vacant time slot of the system must be selected.

At this time, since the communication controller 11 of each mobile station A has a built-in random number generator, a time slot is arbitrarily selected at random according to a random number table, and the time slot number data is input to the CPU 9d. Is done. Then, the mobile station data is transmitted via the transmission unit 10 with the selected time slot number. As described above, since the communication control device 11 of each mobile station A randomly selects its own time slot, even if there are few available time slots in the system as in the related art, a plurality of mobile stations A are simultaneously controlled. The probability that the situation where the station A selects the same time slot occurs can be reduced.

Each mobile station A (for example, mobile stations A and B)
However, even if a situation occurs in which the same time slot is selected, this situation is determined by the base station 1 that has received the signal from each mobile station A. Then, from the base station 1, the numbers of the time slots colliding with each other are transmitted on the master signal. The mobile stations A that have collided with each other that have received the master signal will again randomly select a time slot from the available time slots in the communication control device 11 again. The probability of collision with each other is very low.
The mobile station data is transmitted via the transmission unit 10 in the time slot selected via the CPU 9d.

If the CPU 9d has a random number generator, a signal for selecting another time slot is input from the communication control device 11 to the CPU 9d, and the time slot is stored in the CPU 9d as a random number table. The mobile station data from the communication control device 11 is transmitted via the transmission unit 10 in the selected time slot according to the following. In this way, each mobile station A changes the time slot and rejoins each other.

[0049]

According to a first aspect of the present invention, there is provided a time division multiple access communication method for dividing a communication channel of one carrier frequency into a number of time slots, assigning a user to each time slot, and multiplexing. , A master signal is transmitted at a constant cycle of one data cycle, each receiving station of each user receives the master signal, measures the cycle of one data cycle of the received master signal, and divides this one data cycle. Since the time slot for transmitting the data of the own station is created by dividing into the number of time slots set in the receiving station with reference to the master signal, an expensive reference clock with high accuracy as in the past is used. Is not necessary, and a reference clock with an accuracy of about a quartz clock is sufficient, and the cost of the receiving station equipment is greatly reduced. Furthermore, unlike the conventional system, the entire system is not disturbed by the mobile station whose reference clock is shifted,
A stable system can be constructed.

The second invention is a time division multiple access communication method in which a communication channel of one carrier frequency is divided into a number of time slots, and a user is assigned to each time slot and multiplexed. The master signal is transmitted at a fixed cycle of the data cycle, and each receiving station of each user receives the master signal, measures the cycle of one data cycle of the received master signal, and divides this one data cycle into the master signal. Is divided into the number of time slots set in the receiving station on the basis of the time slot, and a time slot for transmitting data of the own station is created. In each user's receiving station, the position data of the master signal and each receiving station are used. The distance between the base station and the receiving station is obtained from the measured position data of the own station, and from this distance The receiving station obtains the delay time of the received master signal, corrects the time slot created by the delay time, and synchronizes the base station with each receiving station. , And can always be synchronized with the master signal of the base station, so that the conventional guard time can be greatly reduced.

The third invention is a time division multiple access communication method in which a communication channel of one carrier frequency is divided into a number of time slots, and a user is assigned to each time slot for multiplexing. The master signal is transmitted at a fixed cycle of the data cycle, and each receiving station of each user receives the master signal, measures the cycle of one data cycle of the received master signal, and divides this one data cycle into the master signal. Each of the receiving stations generates a time slot for transmitting its own mobile data by dividing the time slot into the number of timeslots set in the receiving station based on the time slot. Randomly selected from the available time slots based on the random number table according to Since each receiving station transmits its own mobile data in the time slot, even if the number of available time slots is small, the time slots of a plurality of receiving stations can be used when joining the system. Is very low. Also, even if
Even if the timeslots of a plurality of receiving stations accidentally collide at the time of joining, the probability of collision at rejoining the system is very low.

The fourth invention is a time division multiple access communication for dividing a communication channel of one carrier frequency into a number of time slots and assigning each time slot to each mobile station mounted on each mobile unit for communication. In the method of transmitting each mobile data to the base station and automatically monitoring a plurality of mobiles by the method, the base station transmits the generated base station data by a master signal at a constant period of one data cycle. The mobile station receives the master signal,
The period of one data cycle of the received master signal is measured, and this one data cycle is divided into the number of time slots set in the mobile station based on the master signal, and the time for transmitting data of the own station is divided. Since the slots are created, and any one of the created time slots is selected to transmit the mobile data of the own station to the base station, the same effect as the first invention is obtained.

According to a fifth aspect of the present invention, the base station transmits the generated base station data by a master signal at a constant period of one data cycle, the mobile station receives the master signal, and receives the master signal. The period of one data cycle is measured, and this one data cycle is divided into the number of time slots set in the mobile station based on the master signal, and time slots for transmitting data of the own station are created. In the mobile station, the distance between the base station and the mobile station is obtained from the position data of the base station identified from the master signal and the position data of the own station measured by the mobile station, and each mobile station receives the distance from this distance. Calculate the delay time of the master signal, correct the time slot created in the own station by this delay time, and synchronize the base station and mobile station. Obtained by way causes, there is the second invention and similar effects.

According to a sixth aspect of the present invention, a base station transmits generated base station data by a master signal at a constant period of one data cycle, a mobile station receives a master signal, and receives the master signal. The period of one data cycle is measured, and this one data cycle is divided into the number of time slots set in the mobile station based on the master signal, and time slots for transmitting data of the own station are created. In the mobile station, the distance between the base station and the mobile station is obtained from the position data of the base station identified from the master signal and the position data of the own station measured by the mobile station, and each mobile station receives the distance from this distance. Calculate the delay time of the master signal, correct the time slot created in the own station by this delay time, and synchronize the base station and mobile station. So that each mobile station has a random number generator,
Each of the mobile stations randomly selects its own time slot from the available time slots based on a random number table by the random number generator, and each mobile station transmits its own mobile data in the selected time slot. Therefore, the same effect as that of the third aspect can be obtained.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an embodiment of the first to tenth inventions.

FIG. 2 is a detailed configuration diagram of a main part of FIG. 1;

FIG. 3 shows an embodiment of the first invention, and is a time chart of each signal.

FIG. 4 shows an embodiment of the second invention, and is a time chart for explaining a time slot synchronization method.

FIG. 5 is an overall configuration diagram of a mobile monitoring system.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 base station 2 base station communication control device 3 base station signal processing unit 4 base station transmission unit 5 base station reception unit 8 mobile station reception unit 7 mobile 9 mobile station signal processing unit 9b for mobile station Peripheral device 9c Slot counter of mobile station 9d CPU of mobile station 10 Transmission unit of mobile station 11 Communication control device of mobile station A, B ... Mobile station of mobile unit 7

Claims (10)

[Claims] 1. A time division multiple access communication method in which a communication channel of one carrier frequency is divided into a number of time slots and a user is assigned to each time slot and multiplexed. A master signal is transmitted at a period, and each receiving station of each user receives the master signal, measures a period of the one data cycle of the received master signal, and divides the one data cycle into the master signal. A time slot for transmitting mobile data of the own station by dividing the time slot into the number of time slots set in the receiving station on the basis of the above. 2. The receiving station of each user obtains a distance between the base station and the receiving station from position data of the master signal and position data of the own station measured by the receiving station. Wherein each of the receiving stations obtains a delay time of the received master signal, and corrects the time slot created by the delay time to synchronize the base station with each of the receiving stations. 2. The time division multiple access method according to 1. 3. The receiving station of each user randomly selects its own time slot based on a random number table by a random number generator, and each receiving station selects its own time slot in the selected time slot. 3. The time division multiple access method according to claim 1, wherein the mobile data is transmitted. 4. A time division multiple access communication method for dividing a communication channel of one carrier frequency into a number of time slots and allocating each time slot to each mobile station mounted on each mobile unit for communication. In the method of automatically subordinately monitoring a plurality of mobile units by transmitting each mobile unit data to a base station, the base station transmits the generated base station data by a master signal at a constant period of one data cycle, and The station receives the master signal, measures the period of the one data cycle of the received master signal, and divides the one data cycle into the number of time slots set in the mobile station based on the master signal. Time slots for transmitting the data of the own station are created by dividing the time slots, and among the created time slots, A method for automatically subordinately monitoring a plurality of mobile units, wherein one of the mobile units is selected and the mobile unit data of the local unit is transmitted to the base station. 5. Each of the mobile stations determines a distance between the base station and the mobile station from position data of the base station identified from the master signal and position data of the own station measured by the mobile station. From this distance, each mobile station calculates the delay time of the received master signal, corrects the time slot created in the own station by this delay time, and synchronizes the base station with the mobile station. The method according to claim 4, wherein the plurality of moving objects are automatically dependently monitored. 6. Each of the mobile stations includes a random number generator, and randomly selects a time slot of the mobile station based on a random number table by the random number generator. 6. The method according to claim 4, wherein each mobile station transmits mobile station data of its own station. 7. A time division multiple access communication method for dividing a communication channel of one carrier frequency into a number of time slots, assigning each time slot to each mobile station mounted on each mobile unit, and performing communication. In a device for automatically and independently monitoring a plurality of mobile units by transmitting data of each mobile unit to a base station, the base station includes a communication control device for creating the base station data, A transmission unit for transmitting the base station data as a master signal in a data cycle repeated at a constant cycle by a communication channel, and a reception unit for receiving a signal transmitted in a time slot selected in each mobile station; The mobile station measures the period of one data cycle of the master signal with a receiving unit that receives the master signal. A frequency divider that divides the measured data cycle into the set number of time slots, a slot counter that counts the number of time slots, a function that sets the number of time slots in one data cycle, A CPU having a function of controlling the frequency divider; a communication control device for creating mobile data; and a transmission unit for transmitting the mobile data created by the communication control device in the selected time slot. An apparatus for automatically subordinate monitoring a plurality of mobile units, wherein the plurality of mobile units are automatically subordinately monitored by transmitting each of the mobile unit data to the base station by a time division multiple access communication method. 8. The plurality of CPUs according to claim 7, wherein the CPU has a function of calculating a delay time of the received master signal to correct a synchronization delay of the created time slot. A device that automatically monitors subordinate moving objects. 9. The CPU according to claim 7, wherein the CPU has a random number generation function for randomly selecting a time slot of the own station based on a random number table. A device that automatically monitors subordinate moving objects. 10. The device according to claim 7, wherein the random number generation function is provided in the communication control device.