JPS61157130A - Polling system - Google Patents

Abstract

PURPOSE:To improve the probability that one set only of a mobile terminal device station of each group exists in each district by allowing a mobile terminal device station side to set a timing of replay to a polling depending on each mobile terminal device station and changing the number of sets in a group giving a replay in a time slot depending on the district and time zone. CONSTITUTION:A radio wave modulated by a district information signal from a sign post is received by a receiver 3 and inputted to a controller 5 via a receiver reception output connection terminal 6. The inputted reception output is demodulated by a demodulator 10, converted into a signal of 1, 0, and fed to a synchronous detection part 11 and a decoding part 12. When the synchronous detection part 11 detects a synchronizing code, the part 11 gives a signal to the decoding part 12, where decoding is executed to store district position information to a storage part 13. A timer part 14 receives position information of district stored by the storage section 13 and time information from a clock part 23, and number of accommodated sets of the group at each district is decided depending on the rate of concentration of each district, and a set output is fed to a slot timer part 19 so as to change the time slot of reply at each mobile terminal device station thereby setting the time slot at each district.

Description

Detailed Description of the Invention (Technical Field) The present invention configures a base station and a large number of mobile terminal stations through a wireless link, and collects data on each mobile terminal station at the base station. number.

The present invention relates to an AVM system in which information such as status is automatically grasped at a base station.

(Prior art and its problems) In one method of the AVM system, a mobile terminal receives radio waves from a sign post that transmits low-power radio waves containing local information and stores location information of the area where it is located. , On the other hand, the base station transmits a polling signal containing location information of the exploration area, and only mobile terminal stations that have stored location information of the area that matches the location information are sent back information such as vehicle number. There are methods to collect data.

For example, in a system such as a taxi business whose main purpose is to efficiently ascertain the vehicle numbers of vacant cars in a short period of time, the system shown in FIG. 3 is adopted.

In other words, mobile terminal stations are divided into n groups in advance.

Each group has a different evening slot,
By transmitting the information signals A1 to An for each group in response to the polling signal P from the base station, consideration is given to shortening the collection time even if the data collection rate is sacrificed to some extent. in this case.

If two or more mobile terminal stations assigned to the same group store location information applicable to polling, they will send back information at the same time in the same time slot, resulting in radio wave congestion and data collection at the base station. become unable. Therefore, the data reception probability is the probability that only one mobile terminal station of each group is located in the corresponding area, and the group is accommodated so that the probability that only one mobile terminal station of each group is located in each area is the highest. It is necessary to decide on the number of units.

For the sake of simplicity, 1. Regarding the operating rate, empty vehicle rate, and vehicle allocation area, which are not related to the present invention. Sign post coverage rate is n100 each
%, and if the number of regions is 89 groups and the number of accommodated devices is m, then under the condition that mobile terminal stations are randomly and evenly distributed in each region, only one mobile terminal station of each group is located in each region. The probability P is P1=rr1/N(1-1/N)''. m may be determined so that the probability P is maximized.

However, depending on regional conditions, the degree of concentration of mobile terminal stations may vary.
Because they are different, they will not be distributed evenly. If the regional concentration coefficient is β, the probability P2 that only one mobile terminal station is located in each region is P2=mβ/N(1-β/N Y'-"
Therefore, P2 differs depending on β.

This means that the optimal conditions cannot be met.

Further, the number of vehicles accommodated in a group M when considering the operating rate and the empty vehicle rate is M=p ab, where the operating rate is a and the empty vehicle rate is a. However, since the operating rate and empty vehicle rate vary depending on the time of day, keeping the number of units accommodated in each group constant does not satisfy the optimal condition of increasing the probability P1 that only one mobile terminal station of each group is located in each region. It turns out.

(Objective) The present invention always satisfies optimal conditions by variably setting the number of cars accommodated in a group depending on the region and time zone.Examples will be described below.

(Embodiment) FIGS. 1 and 2 show an embodiment of the present invention, in which FIG. 2 shows a system diagram of a mobile terminal station device, and FIG. 1 shows a system diagram of a control device.

In Fig. 2, 1 is an antenna, and 2 is an antenna duplexer.

3 is a sign post area signal receiver, 4 is a data transmission radio, and 5 is a control device. Further, 6 in FIG. 1 is a connection terminal for the receiver reception output, 7 is a dual terminal for the radio reception output, 8 is a connection terminal for the radio modulation input, 9 is a connection terminal for the radio transmission control, and 10 is a demodulator, 11 is a synchronization detector, 1
2 is a decoding unit, 13 is a storage unit, 14 is a timer setting unit, 15
is a demodulation section, 16 is a synchronization detection section, 17 is a decoding section, 18 is a comparison section, 19 is a slot timer section, 20 is a modulator, 21
2 is a signal control section, 22 is an encoding section, and 23 is a clock section.

First, the operation shown in FIG. 2 will be explained.

Radio waves from the sign post are sent to antenna 1. The signal passes through the antenna duplexer 2 and is received by the receiver 3, and the received output is supplied to the control device 5. Accordingly, the control device 5 detects the location area. On the other hand, radio waves from the base station are transmitted through antenna 1.
The signal is received by the radio device 4 through the antenna duplexer 2, and the received output is supplied to the control device 5. If the stored area location information matches the exploration area location information included in the radio polling signal from the base station, the control device 5 transmits data such as vehicle number and status to the radio 4° antenna. Shared device 2. Transmit to the base station via antenna 1.

Next, the operation shown in FIG. 1 will be explained.

Radio waves modulated by local information signals from signposts are
The reception output received by the receiver 3 is input to the control device 5 through the receiver reception output connection terminal 6. The input reception output is demodulated by the demodulator 10, n, II
II and II O1+ signals, which are applied to the synchronization detection section 11 and the decoding section 2. When the synchronization detection section 11 detects the synchronization code, it sends a signal to the decoding section 12 for decoding, and stores the local position information in the storage section 13 .

The timer section 14 receives the location information of the region stored in the storage section 13 and the time information from the clock section 23, and determines the number of devices accommodated in each region based on the concentration rate of each region. The setting output is sent to the slot timer section 19 to set the time slot for each region so that the time slot for return transmission changes for each station.

On the other hand, the radio wave modulated by the polling signal from the base station is received by the radio device 4, and its reception output is input to the control device 5 through the radio device reception output connection terminal 7. The input reception output is sent to the demodulator 15.Similarly to the signpost. Synchronization detection section 16. Decrypted by the decryption unit 17 and stored in the storage unit 13
Comparison section 18 with regional information of signposts stored in
are compared.

The comparison unit 18 sends an activation signal to the slot timer unit 19 only when the location information of the exploration area and the location information of the sign post area match. Upon receiving the activation signal, the slot timer section 19 operates according to the settings of the timer setting section 14.
After the set time has elapsed, a signal is sent to the signal control section 21. Upon receiving the signal from the slot timer section 19, the signal control section 21 sends data such as the vehicle number and status encoded by the encoding section 22 to the modulator 20, and also puts the radio 4 into a transmitting state. In order to do this, a signal is output to the radio transmission control terminal 9. Also.

The output of modulator 20 is applied to radio modulation input connection 8 and transmitted back to the base station by radio 4.

(effect) As explained above, according to the method of the present invention.

Since the time slot for return transmission can be changed for each region and time zone, the number of devices that can be accommodated in a group can be changed for each region and time zone, and the probability that only one mobile terminal station is located in each region can be calculated. It is possible to set optimal conditions for increasing the value.

In this explanation, a method was explained in which a mobile terminal station obtains location information of its area from a sign post.

The method of the present invention is also effective even when the information is obtained by manual setting or other communication means.

[Brief explanation of drawings]

FIG. 3 shows a data collection method time chart, FIG. 2 shows a mobile terminal station system diagram, and FIG. 1 shows a control device system diagram. 1: Antenna, 2: Antenna duplexer, 3: Sign post regional signal receiver, 4: Data transmission radio, 5: Control device, 6: Receiver reception output connection terminal. 7: Radio reception output connection terminal, 8: Radio modulation input connection terminal, 9: Radio transmission control connection terminal, 10: Demodulator, 1
1: Synchronization detection unit, 12: Decoding unit, 13: Storage unit, 14:
Timer setting section, 15: Demodulation section, 16: Synchronization detection section, 17
:Decoding section, 18: Comparison section, 19 Nislot timer section, 2
0: Modulator, 21: Signal control section, 22: Encoding section, 23
:Clock section diagram 1

Claims (1)

[Claims] A base station and a large number of mobile terminal stations are configured with wireless lines, and the base station transmits a polling signal, and the mobile terminal stations transmit data in time slots for each group of multiple mobile terminal stations. In this method of collecting data, the mobile terminal station sets the timing at which it returns detected information about the area where its own station is located in response to polling based on clock time information, by changing the timing for each mobile terminal station. , a polling method that is characterized by changing the number of devices that make up the group to be returned in a time slot depending on the region and time zone.